RESUMEN
Effective pest population monitoring is crucial in precision agriculture, which integrates various technologies and data analysis techniques for enhanced decision-making. This study introduces a novel approach for monitoring lures in traps targeting the Mediterranean fruit fly, utilizing air quality sensors to detect total volatile organic compounds (TVOC) and equivalent carbon dioxide (eCO2). Our results indicate that air quality sensors, specifically the SGP30 and ENS160 models, can reliably detect the presence of lures, reducing the need for frequent physical trap inspections and associated maintenance costs. The ENS160 sensor demonstrated superior performance, with stable detection capabilities at a predefined distance from the lure, suggesting its potential for integration into smart trap designs. This is the first study to apply TVOC and eCO2 sensors in this context, paving the way for more efficient and cost-effective pest monitoring solutions in smart agriculture environments.
Asunto(s)
Tephritidae , Compuestos Orgánicos Volátiles , Compuestos Orgánicos Volátiles/análisis , Animales , Tephritidae/fisiología , Dióxido de Carbono/análisis , Control de Insectos/métodos , Control de Insectos/instrumentaciónRESUMEN
Brazil has historically invested few resources in its transport infrastructure, leaving gaps and reducing its efficiency. The country presents a high dependence on road transport, which results in increased operational costs and higher greenhouse gas (GHG) emissions. Consequently, the performance of cargo transportation in Brazil has been deteriorating, accompanied by a rise in the consumption of fossil fuels and noteworthy levels of GHG emissions. This article assesses the carbon intensity of soybean transport operations within Brazil. Utilizing a network equilibrium model, this study estimated the soybean transportation flows that minimize the total cost of transporting this product across the origins and destinations within the grain handling system. The modeling also calculated the GHG emissions in transportation. The results show that the transportation of soybeans produced 2.74 million tonnes of CO2 equivalent annually, with road transport accounting for 81.7% of these emissions. The state of Mato Grosso, responsible for 44.08 kg CO2 equivalent per tonne of soybeans transported, contributed almost 49% of the total emissions due to the extensive distances involved. In contrast, states like Paraná and Rio Grande do Sul, located closer to southern ports, exhibited the lowest emissions, with rates of 11.55 kg CO2 eq/t and 12.52 kg CO2 eq/t, respectively. The analysis highlights the significant potential for reducing GHG emissions by increasing the use of rail and barge transport, particularly in high-emission regions such as Mato Grosso.
Asunto(s)
Contaminantes Atmosféricos , Huella de Carbono , Monitoreo del Ambiente , Glycine max , Gases de Efecto Invernadero , Transportes , Brasil , Gases de Efecto Invernadero/análisis , Monitoreo del Ambiente/métodos , Contaminantes Atmosféricos/análisis , Contaminación del Aire/estadística & datos numéricos , Modelos Teóricos , Dióxido de Carbono/análisisRESUMEN
Global Value Chains (GVCs) significantly influence international trade and environmental outcomes. Despite the economic benefits of GVCs, their impact on the environment remains under-examined. This study analyzes the effects of GVC participation (considering forward and backward positions) on total carbon emissions embodied in exports (TEEE) and imports (TEEI). Utilizing panel data from 65 economies spanning 1995 to 2018, we apply input-output matrices and the system generalized method of moments (GMM-SYS) approach. Our results indicate that GVC participation generally is associated with reductions in TEEI and increases in TEEE, with backward participation exerting a more substantial impact. Furthermore, we observed asymmetrical impacts of GVC participation between developed and developing countries. Developed nations tend to reap greater benefits from GVC in terms of diminished CO2 emissions associated with imports, as well as notable CO2 reductions in both exports and imports, particularly when forward participation is the focal point. Conversely, developing countries grapple with heightened environmental burdens stemming from their engagement in backward linkages.
Asunto(s)
Comercio , Dióxido de Carbono/análisis , Carbono , Países en DesarrolloRESUMEN
Eucalyptus species play an important role in the global carbon cycle, especially in reducing the greenhouse effect as well as storing atmospheric CO2. Thus, assessing the amount of CO2 released by the soil in forest areas can generate important information for environmental monitoring. This study aims to verify the relation between soil carbon dioxide (CO2) flux (FCO2), spectral bands, and vegetation indices (VIs) derived from a UAV-based multispectral camera over an area of eucalyptus species. Multispectral imageries (green, red-edge, and near-infrared) from the Parrot Sequoia sensor, derived vegetation indices, and the FCO2 data from a LI-COR 8100 analyzer, combined with soil moisture and temperature data, were collected and related. The vegetation indices ATSAVI (Adjusted Transformed Soil-Adjusted VI), GSAVI (Green Soil Adjusted Vegetation Index), and SAVI (Soil-Adjusted Vegetation Index), which use soil correction factors, exhibited a strong negative correlation with FCO2 for the species E. camaldulensis, E. saligna, and E. urophylla species. A Multivariate Analysis of Variance showed significance (p < 0.01) for the species factor, which indicates that there are differences when considering all variables simultaneously. The results achieved in this study show a specific correlation between the data of soil CO2 emission and the eucalypt species, providing a distinction of values between the species in the statistical data.
Asunto(s)
Dióxido de Carbono , Eucalyptus , Suelo , Eucalyptus/química , Dióxido de Carbono/análisis , Suelo/química , Monitoreo del Ambiente/métodos , Tecnología de Sensores Remotos/métodos , BosquesRESUMEN
This study aims to address a critical gap in the literature by examining the incorporation of uncertainty in measuring carbon emissions using the greenhouse gas (GHG) Protocol methodology across all three scopes. By comprehensively considering the various dimensions of CO2 emissions within the context of organizational activities, our research contributes significantly to the existing body of knowledge. We address challenges such as data quality issues and a high prevalence of missing values by using information entropy, techniques for order preference by similarity to ideal solution (TOPSIS), and an artificial neural network (ANN) to analyze the contextual variables. Our findings, derived from the data sample of 56 companies across 18 sectors and 13 Brazilian states between 2017 and 2019, reveal that Scope 3 emissions exhibit the highest levels of information entropy. Additionally, we highlight the pivotal role of public policies in enhancing the availability of GHG emissions data, which, in turn, positively impacts policy-making practices. By demonstrating the potential for a virtuous cycle between improved information availability and enhanced policy outcomes, our research underscores the importance of addressing uncertainty in carbon emissions measurement for advancing effective climate change mitigation strategies.
Asunto(s)
Cambio Climático , Gases de Efecto Invernadero , Gases de Efecto Invernadero/análisis , Brasil , Entropía , Monitoreo del Ambiente/métodos , Incertidumbre , Dióxido de Carbono/análisisRESUMEN
Microalgae cultures have emerged as a promising strategy in diverse areas, ranging from wastewater treatment to biofuel production, thus contributing to the search for carbon neutrality. These photosynthetic organisms can utilize the resources present in wastewater and fix atmospheric CO2 to produce biomass with high energy potential. In this study, the removal efficiency of Polycyclic Aromatic Hydrocarbons (PAHs), CO2 fixation and lipid content in the biomass produced from microalgae grown in airlift photobioreactor were evaluated. Four mesoscale cultures were carried out: Control (Seawater + Conway medium), Treatment A (Oil Produced Water + Poultry Effluent Water), Treatment B (Poultry Effluent Water + Seawater) and Treatment C (Oil Produced Water, Seawater and nutrients). The impact of biostimulation, through the addition of nutrients, on PAHs removal efficiency (up to 90%), CO2 fixation rate (up to 0.20 g L-1 d-1) and the composition of the generated biomass was observed. Primarily, the addition of nitrates to the culture medium impacted CO2 fixation rate of the microalgae. In addition, a direct correlation was observed between PAHs removal and lipid accumulation in the biomass, up to 36% in dry weight, demonstrating microalgae's ability to take advantage of the organic carbon (PAHs) present in the culture medium to generate lipid-rich biomass. The concentration of polysaccharides in the biomass obtained did not exceed 12% on a dry weight basis, and the Higher Heating Value (HHV) ranged between 17 and 21 MJ kg-1. Finally, the potential of generating hydrogen through pyrolysis was highlighted, taking advantage of the characteristics of biomass as a conversion route to produce biofuels. These results show that microalgae are effective in wastewater treatment and have great potential in producing biofuels, thus contributing to the transition towards more sustainable energy sources and climate change mitigation.
Asunto(s)
Biocombustibles , Dióxido de Carbono , Microalgas , Fotobiorreactores , Hidrocarburos Policíclicos Aromáticos , Aguas Residuales , Microalgas/metabolismo , Microalgas/crecimiento & desarrollo , Biocombustibles/análisis , Dióxido de Carbono/metabolismo , Dióxido de Carbono/análisis , Aguas Residuales/química , Aguas Residuales/microbiología , Hidrocarburos Policíclicos Aromáticos/metabolismo , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/metabolismo , Biomasa , Eliminación de Residuos Líquidos/métodosRESUMEN
OBJECTIVES: To validate a mathematical model using porous media theory for alveolar CO2 determination in ventilated patients. DESIGN: Mathematical modeling study with prospective clinical validation to simulate CO2 exchange from bloodstream to airway entrance. SETTING: ICU. PATIENTS: Thirteen critically ill patients without chronic or acute lung disease. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Model outcomes compared with patient data showed correlations for end-tidal CO2 (EtCO 2 ), area under the CO2 curve, and Pa CO2 of 0.918, 0.954, and 0.995. Determination coefficients ( R2 ) were 0.843, 0.910, and 0.990, indicating precision and predictive power. CONCLUSIONS: The mathematical model shows potential in pulmonary critical care. Although promising, practical application demands further validation, clinician training, and patient-specific adjustments. The path to clinical use will be iterative, involving validation and education.
Asunto(s)
Dióxido de Carbono , Alveolos Pulmonares , Respiración Artificial , Humanos , Dióxido de Carbono/análisis , Masculino , Persona de Mediana Edad , Femenino , Estudios Prospectivos , Anciano , Alveolos Pulmonares/metabolismo , Unidades de Cuidados Intensivos , Adulto , Modelos Teóricos , Intercambio Gaseoso Pulmonar/fisiología , Enfermedad Crítica/terapia , PorosidadRESUMEN
Atmospheric CO2 enrichment has the potential to improve rice (Oryza sativa L.) yield, but it may also reduce grain nutritional quality, by reducing mineral and protein concentrations. Selenium (Se) fertilization may improve rice grain nutritional composition, but it is not known if this response extends to plants grown in elevated carbon dioxide concentration (eCO2). We conducted experiments to identify the impacts of Se fertilization on yield and quality of rice grains in response to eCO2. The effect of the Se treatment was not significant for the grain yield within each CO2 condition. However, the reduction in macronutrients and micronutrients under eCO2 was mitigated in grains of plants fertilized with Se. Fertilization with Se increased the concentration of Se in roots, flag leaves, and grains independently of atmospheric CO2 concentrations. Elevation of the transcripts of ion transport-related genes could, at least partially, explain the positive relationship between mineral concentrations and grain mass resulting from Se fertilization under eCO2. Treatment with Se also increased the accumulation of total protein in grains under eCO2. Overall, our results revealed that Se fertilization represents a potential asset to maintain rice grain nutritional quality in a future with rising atmospheric CO2 concentration.
Asunto(s)
Dióxido de Carbono , Fertilizantes , Oryza , Selenio , Oryza/crecimiento & desarrollo , Dióxido de Carbono/análisis , Selenio/análisis , Valor Nutritivo , Grano Comestible/química , Grano Comestible/crecimiento & desarrolloRESUMEN
PURPOSE: The Awake Breathing Pattern Assessment (ABPA) is a prototypical clinical grid recently designed through an international consensus of Speech and Language Pathologists (SLPs) to categorize the awake and habitual breathing pattern during the orofacial myofunctional assessment. This cross-sectional study aims to explore the psychometric properties of the ABPA in a preschool population. METHODS: 133 children from 2;11 to 6 years old were assessed with the ABPA. The percentage of time spent breathing through the mouth was objectively measured by a CO2 sensor and used as a baseline measurement. We first performed a multivariate Latent Profile Analysis based on the CO2 measurement and a parental questionnaire to define the number of categories that best characterize the breathing pattern. Subsequently, we assessed the intra- and inter-rater reliability, internal consistency criterion validity, construct validity and sensitivity and specificity. RESULTS: The awake breathing pattern can best be described by two groups: nasal and mouth breathing. The ABPA, initially designed in three groups, was adjusted accordingly. This final version showed excellent intra-rater and inter-rater reliability. There was a significant correlation between the ABPA and the CO2 measurement. The ABPA showed a fair sensitivity and a good specificity. CONCLUSION: The reference tool based on CO2 data was used in children for the first time and was found to be reliable. The ABPA is a suitable tool for SLPs to confirm the diagnosis of mouth breathing in preschool children if more sensitive screening tools, like parental questionnaires, are used beforehand.
Asunto(s)
Respiración por la Boca , Humanos , Respiración por la Boca/diagnóstico , Respiración por la Boca/fisiopatología , Preescolar , Estudios Transversales , Reproducibilidad de los Resultados , Femenino , Masculino , Niño , Psicometría , Sensibilidad y Especificidad , Encuestas y Cuestionarios , Vigilia/fisiología , Respiración , Dióxido de Carbono/análisisRESUMEN
OBJECTIVE: Heart failure is a disease with cardiac dysfunction, and its morbidity and mortality are associated with the degree of dysfunction. The New York Heart Association classifies the heart failure stages based on the severity of symptoms and physical activity. End-tidal carbon dioxide refers to the level of carbon dioxide that a person exhales with each breath. End-tidal carbon dioxide levels can be used in many clinical conditions such as heart failure, asthma, and chronic obstructive pulmonary disease. The aim of the study was to reveal the relationship between end-tidal carbon dioxide levels and the New York Heart Association classification of heart failure stages. METHODS: This study was conducted at Kahramanmaras Sütçü Imam University Faculty of Medicine Adult Emergency Department between 01/03/2019 and 01/09/2019. A total of 80 patients who presented to the emergency department with a history of heart failure or were diagnosed with heart failure during admission were grouped according to the New York Heart Association classification of heart failure stages. The laboratory parameters, ejection fraction values, and end-tidal carbon dioxide levels of the patients were measured and recorded in the study forms. RESULTS: End-tidal carbon dioxide levels and ejection fraction values were found to be significantly lower in the stage 4 group compared to the other groups. Furthermore, pro-B-type natriuretic peptide (BNP) values were found to be significantly higher in stage 4 group compared to the other groups. CONCLUSION: It was concluded that end-tidal carbon dioxide levels could be used together with pro-BNP and ejection fraction values in determining the severity of heart failure.
Asunto(s)
Dióxido de Carbono , Insuficiencia Cardíaca , Índice de Severidad de la Enfermedad , Volumen Sistólico , Humanos , Insuficiencia Cardíaca/clasificación , Insuficiencia Cardíaca/metabolismo , Dióxido de Carbono/análisis , Dióxido de Carbono/metabolismo , Femenino , Masculino , Persona de Mediana Edad , Anciano , Volumen Sistólico/fisiología , Adulto , Volumen de Ventilación Pulmonar/fisiología , Péptido Natriurético Encefálico/sangre , Péptido Natriurético Encefálico/análisis , Pruebas Respiratorias/métodos , Servicio de Urgencia en HospitalRESUMEN
Inland waters are crucial in the carbon cycle, contributing significantly to the global CO2 fluxes. Carbonate lakes may act as both sources and sinks of CO2 depending on the interactions between the amount of dissolved inorganic carbon (DIC) inputs, lake metabolisms, and geochemical processes. It is often difficult to distinguish the dominant mechanisms driving CO2 dynamics and their effects on CO2 emissions. This study was undertaken in three groundwater-fed carbonate-rich lakes in central Spain (Ruidera Lakes), severely polluted with nitrates from agricultural overfertilization. Diel and seasonal (summer and winter) changes in CO2 concentration (CCO2) DIC, and CO2 emissions-(FCO2)-, as well as physical and chemical variables, including primary production and phytoplanktonic chlorophyll-a were measured. In addition, δ13C-DIC, δ13C-CO2 in lake waters, and δ13C of the sedimentary organic matter were measured seasonally to identify the primary CO2 sources and processes. While the lakes were consistently CCO2 supersaturated and FCO2 was released to the atmosphere during both seasons, the highest CCO2 and DIC were in summer (0.36-2.26 µmol L-1). Our results support a strong phosphorus limitation for primary production in these lakes, which impinges on CO2 dynamics. External DIC inputs to the lake waters primarily drive the CCO2 and, therefore, the FCO2. The δ13C-DIC signatures below -12 confirmed the primary geogenic influence on DIC. As also suggested by the high values on the calcite saturation index, the Miller-Tans plot revealed that the CO2 source in the lakes was close to the signature provided by the fractionation of δ13C-CO2 from calcite precipitation. Therefore, the main contribution behind the CCO2 values found in these karst lakes should be attributed to the calcite precipitation process, which is temperature-dependent according to the seasonal change observed in δ13C-DIC values. Finally, co-precipitation of phosphate with calcite could partly explain the observed low phytoplankton production in these lakes and the impact on the contribution to increasing greenhouse gas emissions. However, as eutrophication increases and the soluble reactive phosphorus (SRP) content increases, the co-precipitation of phosphate is expected to be progressively inhibited. These thresholds must be assessed to understand how the CO32- ions drive lake co-precipitation dynamics. Carbonate regions extend over 15% of the Earth's surface but seem essential in the CO2 dynamics at a global scale.
Asunto(s)
Dióxido de Carbono , Lagos , Estaciones del Año , Lagos/química , Dióxido de Carbono/análisis , Dióxido de Carbono/metabolismo , España , Monitoreo del Ambiente/métodos , Ciclo del Carbono , Fitoplancton/metabolismoRESUMEN
This study examines the gasification kinetics of Brazilian municipal solid waste (MSW) and its components under air, CO2, and air/CO2 (70/30 vol%) atmospheres. The ignition indices of paper and plastic are 6 and 3 times that of food waste, which are 38.6 × 10-3 %/min3 and 19.6 × 10-3 %/min3, respectively, implying a faster separation of volatile compounds from the paper and plastic. The minimum Eα values of 132 kJ/mol and 140 kJ/mol have been obtained for paper waste under air and air/CO2, respectively. On CO2 condition, MSW has an average Ea value of 96 kJ/mol. Under an air/CO2 atmosphere, a high synergistic ΔW of -4.7 wt% has been identified between individual components. The presence of air and CO2 improves the oxidation and char gasification process, thus resulting in better combustion. Hence, the gasification of MSW under an air/CO2 atmosphere would improve the waste-to-energy plant's performance and minimize the CO2 emission.
Asunto(s)
Dióxido de Carbono , Residuos Sólidos , Termogravimetría , Brasil , Cinética , Dióxido de Carbono/análisis , Eliminación de Residuos/métodos , Atmósfera/química , Gases , CiudadesRESUMEN
Mangroves forests may be important sinks of carbon in coastal areas but upon their death, these forests may become net sources of carbon dioxide (CO2) and methane (CH4) to the atmosphere. Here we assessed the spatial and temporal variability in soil CO2 and CH4 fluxes from dead mangrove forests and paired intact sites in SE-Brazil. Our findings demonstrated that during warmer and drier conditions, CO2 soil flux was 183 % higher in live mangrove forests when compared to the dead mangrove forests. Soil CH4 emissions in live forests were > 1.4-fold higher than the global mangrove average. During the wet season, soil GHG emissions dropped significantly at all sites. During warmer conditions, mangroves were net sources of GHG, with a potential warming effect (GWP100) of 32.9 ± 10.2 (±SE) Mg CO2e ha-1 y-1. Overall, we found that dead mangroves did not release great amounts of GHG after three years of forest loss.
Asunto(s)
Dióxido de Carbono , Monitoreo del Ambiente , Gases de Efecto Invernadero , Metano , Suelo , Humedales , Brasil , Gases de Efecto Invernadero/análisis , Suelo/química , Dióxido de Carbono/análisis , Metano/análisis , BosquesRESUMEN
Peatlands are recognized as crucial greenhouse gas sources and sinks and have been extensively studied. Their emissions exhibit high spatial heterogeneity when measured on site using flux chambers. However, the mechanism by which this spatial variability behaves on a very fine scale remains unclear. This study investigates the fine-scale spatial variability of greenhouse gas emissions from a subantarctic Sphagnum peatland bog. Using a recently developed skirt chamber, methane emissions and ecosystem respiration (as carbon dioxide) were measured at a submeter scale resolution, at five specific 3 × 3 m plots, which were examined across the site throughout a single campaign during the Austral summer season. The results indicated that methane fluxes were significantly less homogeneously distributed compared with ecosystem respiration. Furthermore, we established that the spatial variation scale, i.e., the minimum spatial domain over which notable changes in methane emissions and ecosystem respiration occur, was <0.56 m2. Factors such as ground height relative to the water table and vegetation coverage were analyzed. It was observed that Tetroncium magellanicum exhibited a notable correlation with higher methane fluxes, likely because of the aerenchymatous nature of this species, facilitating gas transport. This study advances understanding of gas exchange patterns in peatlands but also emphasizes the need for further efforts for characterizing spatial dynamics at a very fine scale for precise greenhouse gas budget assessment.
Asunto(s)
Gases de Efecto Invernadero , Metano , Humedales , Gases de Efecto Invernadero/análisis , Metano/análisis , Dióxido de Carbono/análisis , Suelo/química , Ecosistema , Sphagnopsida , Monitoreo del AmbienteRESUMEN
The conversion of native vegetation to agricultural areas leads to a natural process of carbon loss but these systems can stabilize in terms of carbon dynamics depending on the management and conversion time, presenting potential to both store and stabilize this carbon in the soil, resulting in lower soil respiration rates. In this context, this study aimed to investigate the effect of converting native Cerrado forest areas to agricultural systems with a forest planted with Eucalyptus camaldulensis and silvopastoral systems on the dynamics of CO2 emission and carbon stock at different soil depths. The experimental sites are located in the Midwest of Brazil, in the coordinates 20°22'31â³ S and 51°24'12â³ W. Were evaluated soil CO2 emission (FCO2), soil organic carbon, the degree of humification of soil organic matter (HLIFS), soil temperature, soil moisture, and soil chemical and physical attributes. The soil of the area is classified as an Oxisol (Haplic Acrustox). Soil samples were collected at depths of 0.00-0.10, 0.10-0.20, 0.20-0.30, and 0.30-0.40 m. The lowest FCO2 values were found in the silvopastoral system (1.05 µmol m-2 s-1), followed by the native forest (1.65 µmol m-2 s-1) and the eucalyptus system (1.96 µmol m-2 s-1), indicating a 36% reduction in FCO2 compared to the conversion of the native forest to the silvopastoral system and an increase of 19% when converting the native forest to the eucalyptus system. The soil chemical attributes (N, K+, Ca2+, H++Al3+, CEC, and organic carbon) showed a decrease along the profile. The shallowest depths (0.00-0.10 and 0.10-0.20 m) presented no differences between systems but the subsequent depths (0.20-0.30 and 0.30-0.40 m) had a difference (95% confidence interval), relative to N, Ca2+, H++Al3, CEC, and organic carbon stock (OCS), and the soil under silvopastoral system showed a higher concentration of these attributes than the native forest. The multivariate analysis showed that the eucalyptus and silvopastoral systems did not differ from the forest in the shallowest soil layer but differed from each other. This behavior changed from the second assessed depth (0.10-0.20 m), in which the silvopastoral system stands out, differing both from the eucalyptus system and from the native forest, and this behavior is maintained at the following depths (0.20-0.30 and 0.30-0.40 m). OCS, H++Al3, CEC, and nitrogen are strongly related to land use change for silvopastoral system. Regarding the behavior/relationship of attributes as a function of depth, the silvopastoral system contributed to soil carbon accumulation and stability over consecutive years.
Asunto(s)
Agricultura , Dióxido de Carbono , Carbono , Bosques , Suelo , Suelo/química , Carbono/análisis , Dióxido de Carbono/análisis , Brasil , EucalyptusRESUMEN
The primary energy consumption structure of BRICS countries is dominated by fossil energy, particularly coal. Coal consumption in BRICS countries is a major driver underlying increased carbon emissions. Therefore, this study developed a spatiotemporal decoupling mode and incorporated factors related to coal consumption-induced carbon emissions into a spatiotemporal decoupling analysis method to provide differentiated and targeted policies for energy restructuring and emission reduction targets in BRICS countries. Moreover, a temporal-spatial decomposition logarithmic mean Divisia index model was developed using the spatiotemporal decoupling index method. The model is based on CO2 emissions generated by coal consumption in BRICS countries, with a primary focus on data from Brazil, Russia, South Africa, India, and China. The findings reveal distinct spatiotemporal distributions and driving effects of coal consumption and carbon dioxide emissions across various countries. Factors such as CO2 emission intensity, coal consumption intensity, economic output per capita, and population structure exerted either positive or negative effects on the distributional effect of the carbon emission-economic output per capita association in BRICS countries. Additionally, country-level heterogeneity in the influence of the distributional effects of CO2 emissions was observed within each BRICS country. Thus, different policies are needed to achieve carbon emission reduction targets in different countries.
Asunto(s)
Carbón Mineral , Desarrollo Económico , Carbón Mineral/análisis , Dióxido de Carbono/análisis , Brasil , ChinaRESUMEN
The production of biofuels to be used as bioenergy under combustion processes generates some gaseous emissions (CO, CO2, NOx, SOx, and other pollutants), affecting living organisms and requiring careful assessments. However, obtaining such information experimentally for data evaluation is costly and time-consuming and its in situ obtaining for regional biomasses (e.g., those from Northeast Brazil (NEB) is still a major challenge. This paper reports on the application of artificial neural networks (ANNs) for the prediction of the main air pollutants (CO, CO2, NO, and SO2) produced during the direct biomass combustion (N2/O2:80/20%) with the use of ultimate analysis (carbon, hydrogen, nitrogen, sulfur, and oxygen). 116 worldwide biomasses were used as input data, which is a relevant alternative to overcome the lack of experimental resources in NEB and obtain such information. Cross-validation was conducted with k-fold to optimize the ANNs and performance was analyzed with the use of statistical errors for accuracy assessments. The results showed an acceptable statistical performance for all architectures of ANNs, with 0.001-12.41% MAPE, 0.001-5.82 mg Nm-3 MAE, and 0.03-52.30 mg Nm-3 RMSE, highlighting the high precision of the emissions studied. On average, the differences between predicted and real values for CO, CO2, NO, and SO2 emissions from NEB biomasses were approximately 0.01%, 10-6%, 0.14%, and 0.05%, respectively. Pearson coefficient provided consistent results of concentration of the ultimate analysis in relation to the emissions studied and effectiveness of the test set in the developed models.
Asunto(s)
Contaminantes Atmosféricos , Contaminantes Atmosféricos/análisis , Biomasa , Dióxido de Carbono/análisis , Gases/análisis , Redes Neurales de la ComputaciónRESUMEN
There are various climate policies to decarbonize the energy matrix of a country. In the case of Chile, a carbon tax of 5 USD/tCO2 was initially implemented, and later, a schedule was established for the phase-out of coal-fired thermoelectric plants, all the above in the absence of subsidies for non-conventional renewable energy (NCRE). This study uses a computable general equilibrium (CGE) model and microsimulations to assess the contribution of current climate policies and other more demanding scenarios that accelerate the decarbonization of the Chilean energy matrix, considering economic, environmental, and distributional impacts. Specifically, carbon taxes are simulated with and without complementary climate policies (phase-out of coal-fired power plants and NCRE subsidies). The results show that the scenarios that combine the three climate policies generate a greater decrease in greenhouse gas emissions (40.4% â¼ 57.5%). Besides, the drop in GDP is more pronounced when coal-fired thermoelectric plants phase out (0.3% additional), and NCRE subsidies contribute to moderately reducing emissions. However, NCRE subsidies reduce the negative effect on households' expenditure and income, especially in the poorest quintile. Finally, microsimulations show marginal changes in income distribution and an increase of up to 0.4 percentage points in the poverty rate.
Asunto(s)
Carbono , Carbón Mineral , Chile , Centrales Eléctricas , Energía Renovable , Impuestos , Dióxido de Carbono/análisisRESUMEN
Assessing the impact of greenhouse gas (GHG) emissions on agricultural soils is crucial for ensuring food production sustainability in the global effort to combat climate change. The present study delves to comprehensively assess GHG emissions in Cuba's agricultural soil and analyze its implications for rice production and climate change because of its rich agriculture cultivation tradition and diverse agro-ecological zones from the period of 1990-2022. In this research, based on Autoregressive Distributed Lag (ARDL) approach the empirical findings depicts that in short run, a positive and significant impact of 1.60 percent % in Cuba's rice production. The higher amount of atmospheric carbon dioxide (CO2) levels improves photosynthesis, and stimulates the growth of rice plants, resulting in greater grain yields. On the other hand, rice production index raising GHG emissions from agriculture by 0.35 % in the short run. Furthermore, a significant and positive impact on rice production is found in relation to the farm machinery i.e., 3.1 %. Conversely, an adverse and significant impact of land quality was observed on rice production i.e., -5.5 %. The reliability of models was confirmed by CUSUM and CUSUM square plot. Diagnostic tests ensure the absence of serial correlation and heteroscedasticity in the models. Additionally, the forecasting results are obtained from the three machine learning models i.e. feed forward neural network (FFNN), support vector machines (SVM) and adaptive boosting technique (Adaboost). Through the % MAPE criterion, it is evident that FFNN has achieved high precision (91 %). Based on the empirical findings, the study proposed the adoption of sustainable agricultural practices and incentives should be given to the farmers so that future generations inherit a world that is sustainable, and healthy.
Asunto(s)
Gases de Efecto Invernadero , Oryza , Suelo , Gases de Efecto Invernadero/análisis , Cambio Climático , Reproducibilidad de los Resultados , Metano/análisis , Agricultura/métodos , Dióxido de Carbono/análisis , Óxido Nitroso/análisisRESUMEN
Mosses of the genus Sphagnum are the dominant vegetation in most pristine peatlands in temperate and high-latitude regions. They play a crucial role in carbon sequestration, being responsible for ca. 50% of carbon accumulation through their active participation in peat formation. They have a significant influence on the dynamics of CO2 emissions due to an efficient maximum potential photosynthetic rate, lower respiration rates, and the production of a recalcitrant litter whose decomposition is gradual. However, various anthropogenic disturbances and land use management actions that favor its reestablishment have the potential to modify the dynamics of these CO2 emissions. Therefore, the objective of this review is to discuss the role of Sphagnum in CO2 emissions generated in peatland ecosystems, and to understand the impacts of anthropogenic practices favorable and detrimental to Sphagnum on these emissions. Based on our review, increased Sphagnum cover reduces CO2 emissions and fosters C sequestration, but drainage transforms peatlands dominated by Sphagnum into a persistent source of CO2 due to lower gross primary productivity of the moss and increased respiration rates. Sites with moss removal used as donor material for peatland restoration emit twice as much CO2 as adjacent undisturbed natural sites, and those with commercial Sphagnum extraction generate almost neutral CO2 emissions, yet both can recover their sink status in the short term. The reintroduction of fragments and natural recolonization of Sphagnum in transitional peatlands, can reduce emissions, recover, or increase the CO2 sink function in the short and medium term. Furthermore, Sphagnum paludiculture is seen as a sustainable alternative for the use of transitional peatlands, allowing moss production strips to become CO2 sink, however, it is necessary to quantify the emissions of all the components of the field of production (ditches, causeway), and the biomass harvested from the moss to establish a final closing balance of C.