A Comprehensive Approach for Designing Low Carbon Wood Bio-Concretes.

This paper presents a method for designing low carbon bio-based building materials, also named bio-concretes, produced with wood wastes in shavings form (WS) and cementitious pastes. As the aggregates phase of bio-concretes is composed of plant-based particles, known as porous and high water-absorbing materials, the bio-concretes cannot be designed by using the traditional design rules used for conventional mortar or concrete. Then, the method used in the current paper is an adaptation of a previous one that has been developed in a recent paper where bio-concretes were produced with a cement matrix, three types of bio-aggregates, and a proposal of a design abacus. However, when that abacus is used for designing WBC with low cement content in the matrix, the target compressive strength is not reached. In the present paper, the method is extended to low cement content matrix (up to 70% of cement substitution) and also considering the greenhouse gas (GHG) emission of the WBC. To obtain data for proposing a new design abacus, an experimental program was carried out by producing nine workable WBCs, varying wood volumetric fractions (40-45-50%), and water-to-binder ratios. The bio-concretes produced presented adequate consistency, lightness (density between 715 and 1207 kg/m3), and compressive strength ranging from 0.64 to 12.27 MPa. In addition, the GHG emissions of the WBC were analysed through the Life Cycle Assessment methodology. From the relationships obtained between density, compressive strength, water-to-binder ratio, cement consumption, and GHG emissions of the WBC, calibration constants were proposed for developing the updated and more complete abacus regarding an integrated mix design methodology.

Assessing methane emissions from paddy fields through environmental and UAV remote sensing variables.

Concerns about methane (CH4) emissions from rice, a staple sustaining over 3.5 billion people globally, are heightened due to its status as the second-largest contributor to greenhouse gases, driving climate change. Accurate quantification of CH4 emissions from rice fields is crucial for understanding gas concentrations. Leveraging technological advancements, we present a groundbreaking solution that integrates machine learning and remote sensing data, challenging traditional closed chamber methods. To achieve this, our methodology involves extensive data collection using drones equipped with a Micasense Altum camera and ground sensors, effectively reducing reliance on labor-intensive and costly field sampling. In this experimental project, our research delves into the intricate relationship between environmental variables, such as soil conditions and weather patterns, and CH4 emissions. We achieved remarkable results by utilizing unmanned aerial vehicles (UAV) and evaluating over 20 regression models, emphasizing an R2 value of 0.98 and 0.95 for the training and testing data, respectively. This outcome designates the random forest regressor as the most suitable model with superior predictive capabilities. Notably, phosphorus, GRVI median, and cumulative soil and water temperature emerged as the model's fittest variables for predicting these values. Our findings underscore an innovative, cost-effective, and efficient alternative for quantifying CH4 emissions, marking a significant advancement in the technology-driven approach to evaluating rice growth parameters and vegetation indices, providing valuable insights for advancing gas emissions studies in rice paddies.

Livestock intensification and environmental sustainability: An analysis based on pasture management scenarios in the brazilian savanna.

Brazil's major beef production occurs in the Cerrado, predominantly as extensive pastures that covers ∼50 Mha of the biome, of which approximately 2/3 show signs of degradation. Pasture recovery is now a key environmental policy, as it improves land use efficiency and soil carbon sequestration. However, as intensification leads to higher cattle stocking rates and external inputs (fertilizers, liming, etc.), the impact of improved pastures on greenhouse gas mitigation is still debatable. This study focused on the Cerrado biome and aimed to (i) quantify soil carbon stock changes under different scenarios of management and recovery of degraded pastures. In addition, (ii) the potential for capturing carbon in the soil to mitigate emissions of greenhouse gases (GHG) by the intensification of pastures was evaluated. Soil C stock changes (0-20 cm) were assessed using the Century model version 4.5, which had been previously validated for the region. Model parameters were adjusted for three pastures classes (degraded, intermediately degraded, and not degraded) within a time-series (1985-2020) of land use maps for the Cerrado, serving as baselines. Scenarios of pasture intensification were modeled against these baselines, and an analysis was carried out on the estimated changes in soil C stock and greenhouse gas balance. Before the intensification scenario (year 2020), the total carbon stock was estimated to be ∼1830 Mt for the whole pasture area, whose spatial distribution corresponded to edaphoclimatic contrasts and pasture conditions. The highest soil organic carbon stocks were observed in the non-degraded pastures. With the increase in carrying capacity, beef production is estimated to potentially increase by 1/3 due to the recovery of degraded areas through intensive management. This increase would be sufficient to meet the projected ∼12% increase in Brazil's livestock production by the end of the decade if all pasture areas are restored, which is much possibly an unrealistic scenario as not all degraded areas are suitable for crops or can successfully improve pasture yield. In addition, the increase in soil C stocks was only sufficient to compensate for 27% and 42% of the GHG emissions resulting from intensification in areas with intermediate and severe degradation, respectively. Therefore, to strike a balance between economic considerations and environmental impact, additional strategies are needed to reduce GHG emissions and/or enhance C sinks, such as increasing tree density on farms. From this perspective, implementing livestock intensification at the landscape scale can promote C stocks and the diversity of ecosystem services, opening the possibility of ecosystem restoration.

Estimating the carbon footprint of Mexican food consumption based on a high-resolution environmentally extended input-output model.

Increased global attention is being paid to the food-health-climate trilemma. In this study, we evaluate the climate impacts of Mexico's food consumption patterns by creating a high-resolution (262 sectors) Environmentally Extended Input-Output (EEIO) model called MXEEIO. We focus on the differences between food away from home (FAFH) and food at home (FAH) and compare Mexico's results with those of the USA. The results show that the main components of food spending in Mexico were meat, baked products, and beverages, raising concerns about their potential negative health effects if consumed excessively. Mexico's total greenhouse gas (GHG) emissions from food consumption were estimated at 149 million metric tons (MMT) in 2013, as opposed to 797 MMT for the USA. Meat and dairy products were the main contributors to Mexico's food-related GHG emissions, accounting for 57% of total emissions. Mexico spent a much smaller proportion of food-related income on FAFH than the USA (13% vs. 52%), suggesting great potential for growth as Mexico's per capita GDP continues to rise. Detailed contribution analysis shows that reducing Mexico's food-related GHG emissions would benefit most from a transition to low-carbon cattle farming, but mitigation efforts in other sectors such as crop cultivation and electricity generation are also important. Overall, our study underscores the significance of food-related GHG emissions in Mexico, especially those from meat and dairy products, and the mitigation challenges these sectors face.

Assessing greenhouse gas emissions in Cuban agricultural soils: Implications for climate change and rice (Oryza sativa L.) production.

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.

Greenhouse gas mitigation scenarios in the solid waste sector for compliance with the Brazilian NDC: Case study of the Recife metropolitan area, Brazil.

The Intergovernmental Panel on Climate Change (IPCC) indicates that the waste sector is a potential emitter of methane gas (CH4), which has a greenhouse effect up to 28 times greater than that of carbon dioxide (CO2). The management of municipal solid waste (MSW) generates greenhouse gases (GHG) directly through emissions from the process itself as well as indirectly through transportation and energy consumption. The objective of this study was to evaluate the GHG emissions contributed by the waste sector in the Recife metropolitan region (RMR) and to define mitigation scenarios to comply with the Brazilian Nationally Determined Contribution (NDC), a result of the Paris Agreement. To achieve this, an exploratory study was carried out, including a literature review, collection of data, estimation of emissions using the IPCC model (2006), and comparison between the values assumed by the country in 2015 and those estimated in the adopted mitigation scenarios. The RMR is composed of 15 municipalities, has an area of 3,216,262 km2 and a population of 4,054,866 inhabitants (2018), generating approximality 1.4 million t-year of MSW. It was estimated that, in the period from 2006 to 2018, 25.4 million tCO2e were emitted. The comparative analysis between the absolute values defined in the Brazilian NDC and the results from the mitigation scenarios showed that approximately 36 million tCO2e could be avoided through the disposal of MSW in the RMR, equivalent to a 52% reduction in emissions estimated for 2030, a percentage greater than the 47% reduction assumed in the Paris Agreement.

Estimación de emisiones de gases de efecto invernadero en la dieta de mujeres adolescentes en áreas rurales de oriente de Guatemala / Estimation of greenhouse of gas emissions in the diet of adolescent women in rural areas of eastern Guatemala

Introducción. La producción de alimentos es una de las principales causas de Emisiones de Gases de Efecto Invernadero (GEI). Estimar las emisiones GEI de la dieta es el punto de partida para definir dietas saludables y sostenibles con el ambiente. Objetivo. Estimar el total GEI de la dieta de mujeres adolescentes del oriente de Guatemala, así como la contribución de grupos de alimentos a este valor. Materiales y métodos. En el contexto de un estudio de agricultura y nutrición en el oriente de Guatemala, se realizó un análisis secundario de los datos dietéticos (Recordatorio de 24 horas) de 2082 mujeres adolescentes. Los alimentos reportados fueron enlazados con la base de datos SHARP, que contiene estimaciones de GEI para 944 alimentos. La variable de enlace fue un código único armonizado con el sistema de clasificación FoodEx2. Resultados. La dieta es poco diversa, principalmente a base de grupos de alimentos de origen vegetal, con poca presencia de alimentos de origen animal. El GEI de la dieta fue de 2,3 Kg CO2 eq/ per cápita/día, con la mayor contribución de comidas preparadas (26,7%) y panes, tortillas y similares (12,8%). Conclusiones. La dieta de las mujeres adolescentes de áreas rurales de Guatemala tiene un GEI inferior al reportado en otros países de la región para estratos socioeconómicos con mayor consumo de alimentos de origen animal. Este estudio es el punto de partida para sistematizar la metodología para continuar con las estimaciones de GEI en Guatemala(AU)

Introduction. Food production is one of the main causes of Greenhouse Gas Emissions (GHGE). Estimating GHG emissions from the diet is the starting point for defining healthy and environmentally sustainable diets. Objective. Estimate the total GHGE in the diet of adolescent women from eastern Guatemala, as well as the contribution of food groups to this value. Materials and methods. In the context of an agriculture and nutrition study in eastern Guatemala, a secondary analysis of dietary data (24-hour recall) of 2082 adolescent women was performed. The reported foods were linked to the SHARP database, which contains GHGE estimates for 944 foods. The linking variable was a unique code harmonized with the FoodEx2 classification system. Results. The diet is not diverse, mainly based on food groups of plant origin, with little presence of foods of animal origin. The GHG of the diet was 2.3 Kg CO2 eq/per capita/day, with the greatest contribution from prepared foods (26.7%) and breads, tortillas and similar products (12.8%). Conclusions. The diet of adolescent women in rural areas of Guatemala has a lower GHG than that reported in other countries in the region for socioeconomic strata with greater consumption of foods of animal origin. This study is the starting point to systematize the methodology to continue with GHG estimates in Guatemala(AU)

Carbon Storage in Different Compartments in Eucalyptus Stands and Native Cerrado Vegetation.

This study evaluated Carbon (C) storage in different compartments in eucalyptus stands and native Cerrado vegetation. To determine C above ground, an inventory was carried out in the areas where diameter at breast height (DBH), diameter at base height (Db), and total tree height (H) were measured. In the stands, the rigorous cubage was made by the direct method, and in the native vegetation, it was determined by the indirect method through an allometric equation. Roots were collected by direct method using circular monoliths to a depth of 60 cm and determined by the volume of the cylinder. Samples were collected up to 100 cm deep to estimate C stock in the soil. All samples collected directly had C determined using the CHNS elemental analyzer. Gas samples were collected using a manually closed chamber, and the gas concentration was determined by gas chromatography. The results indicate high C storage in the studied areas > 183.99 Mg ha-1, could contribute to CO2 mitigation > 674.17 Mg ha-1. In addition to low emissions (<1 kg ha-1 yr-1) for the three evaluated areas, with no statistical difference in relation to the Global Warming Potential. Concerning the native cerrado vegetation conversion, the "4-year-old eucalyptus stand" seemed to restore the original soil carbon stocks in the first-meter depth, regardless of some losses that might have occurred right after establishment. Conversely, a significant loss of carbon in the soil was observed due to the alternative setting, where similar natural land was converted into agriculture, mostly soybean, and then, years later, turned into the "6-year-old eucalyptus stand" (28.43 Mg ha-1). Under this study, these mixed series of C baselines in landscape transitions have reflected on unlike C dynamics outcomes, whereas at the bottom line, total C stocks were higher in the younger forest (4-year-old stand). Therefore, our finding indicates that we should be thoughtful regarding upscaling carbon emissions and sequestration from small-scale measurements to regional scales.

Regulation of CO2 by the sea in areas around Latin America in a context of climate change.

Anthropogenic activities are increasing the atmospheric carbon dioxide (CO2); around a third of the CO2 emitted by these activities has been taken up by the ocean. Nevertheless, this marine ecosystem service of regulation remains largely invisible to society, and not enough is known about regional differences and trends in sea-air CO2 fluxes (FCO2), especially in the Southern Hemisphere. The objectives of this work were as follows: first to put values of FCO2 integrated over the exclusive economic zones (EEZ) of five Latin-American countries (Argentina, Brazil, Mexico, Peru, and Venezuela) into perspective regarding total country-level greenhouse gases (GHG) emissions. Second, to assess the variability of two main biological factors affecting FCO2 at marine ecological time series (METS) in these areas. FCO2 over the EEZs were estimated using the NEMO model, and GHG emissions were taken from reports to the UN Framework Convention on Climate Change. For each METS, the variability in phytoplankton biomass (indexed by chlorophyll-a concentration, Chla) and abundance of different cell sizes (phy-size) were analyzed at two time periods (2000-2015 and 2007-2015). Estimates of FCO2 at the analyzed EEZs showed high variability among each other and non-negligible values in the context of greenhouse gas emissions. The trends observed at the METS indicated, in some cases, an increase in Chla (e.g., EPEA-Argentina) and a decrease in others (e.g., IMARPE-Peru). Evidence of increasing populations of small size-phytoplankton was observed (e.g., EPEA-Argentina, Ensenada-Mexico), which would affect the carbon export to the deep ocean. These results highlight the relevance of ocean health and its ecosystem service of regulation when discussing carbon net emissions and budgets.

Effect of Tithonia diversifolia (Hemsl.) A. Gray intake on in vivo methane (CH4) emission and milk production in dual-purpose cows in the Colombian Amazonian piedmont.

The inclusion of Tithonia diversifolia in pasture-based diets is a promising alternative to increase bovine productivity, due to its chemical composition and wide adaptation, but there are few in vivo studies to determine its effect on methane yield and animal production in grazing systems. The objective of this study was to determine the effects of the T. diversifolia inclusion in a basal diet of Brachiaria humidicola on methane (CH4) emissions by enteric fermentation, and on milk yield and quality in dual-purpose cows. The polytunnel technique was used for the determination of methane yield and two diets were evaluated (Diet 1: Brachiaria humidicola 100%; Diet 2: T. diversifolia 15% + B. humidicola 85% dry matter basis) in the moderate rainy and rainy seasons using a cross-over experimental design; milk production was measured by daily milk weighing, and milk quality was determined using a LACTOSCAN analyzer. The inclusion of T. diversifolia did not increase the dry matter intake (P = 0.369), but increased the intake of crude protein and minerals, and reduced fiber intake, resulting in the increased yield of milk and its components in the moderate rainy season (P = 0.012). The inclusion of T. diversifolia reduced the absolute CH4 emissions (P = 0.016), Ym and emission intensity (per unit of fat, protein and kilogram fat and protein corrected milk yields) both in the moderate rainy and rainy seasons (P < 0.05). We conclude that the inclusion of T. diversifolia in the forage feed base in the humid tropics such as the Amazon piedmont can be used as a tool to both mitigate enteric CH4 emissions and to increase animal productivity and hence reduce emissions intensity, and thus reduce pressure on the agricultural frontier in critical areas such as the Amazon.

Greenhouse gas balance and mitigation of pasture-based dairy production systems in the Brazilian Atlantic Forest Biome.

Brazilian cattle production is mostly carried out in pastures, and the need to mitigate the livestock's greenhouse gas (GHG) emissions and its environmental footprint has become an important requirement. The adoption of well-suited breeds and the intensification of pasture-based livestock production systems are alternatives to optimize the sector's land use. However, further research on tropical systems is necessary. The objective of this research was to evaluate the effect of Holstein (HO) and Jersey-Holstein (JE x HO) crossbred cows in different levels of pasture intensification (continuous grazing system with low stocking rate-CLS; irrigated rotational grazing system with high stocking rate-RHS), and the interaction between these two factors on GHG mitigation. Twenty-four HO and 24 JE x HO crossbred dairy cows were used to evaluate the effect of two grazing systems on milk production and composition, soil GHG emissions, methane (CH4) emission, and soil carbon accumulation (0-100 cm). These variables were used to calculate carbon balance (CB), GHG emission intensity, the number of trees required to mitigate GHG emission, and the land-saving effect. The number of trees necessary to mitigate GHG emission was calculated, considering the C balance within the farm gate. The mitigation of GHG emissions comes from the annual growth rate and accumulation of C in eucalyptus trees' trunks. The CB of all systems and genotypes presented a deficit in carbon (C); there was no difference for genotypes, but RHS was more deficient than CLS (-4.99 to CLS and -28.72 to RHS ton CO2e..ha-1.year-1). The deficit of C on GHG emission intensity was similar between genotypes and higher for RHS (-0.480 to RHS and -0.299 to CLS kg CO2e..kg FCPCmilk-1). Lower GHG removals (0.14 to CLS higher than 0.02 to RHS kg CO2e..kg FCPCmilk-1) had the greatest influence on the GHG emission intensity of milk production. The deficit number of trees to abatement emissions was higher to HO (-46.06 to HO and -38.37 trees/cow to JE x HO) and to RHS (-51.9 to RHS and -33.05 trees/cow to CLS). However, when the results are expressed per ton of FCPCmilk, there was a difference only between pasture management, requiring -6.34 tree. ton FCPCmilk-1 for the RHS and -3.99 tree. ton FCPCmilk-1 for the CLS system. The intensification of pastures resulted in higher milk production and land-saving effect of 2.7 ha. Due to the reservation of the pasture-based dairy systems in increasing soil C sequestration to offset the GHG emissions, especially enteric CH4, planting trees can be used as a mitigation strategy. Also, the land-save effect of intensification can contribute to the issue, since the area spared through the intensification in pasture management becomes available for reforestation with commercial trees.

Greenhouse gas mitigation and carbon sequestration potential in humid grassland ecosystems in Brazil: A review.

Climate change is a major constraint on the sustainability of the humid tropics, maintaining ecosystem services, food production, and social functioning. Humid tropics play an essential role in C storage and greenhouse gas (GHG) emission reduction. Unfortunately, unplanned economic exploration, human occupation, and lack of knowledge of techniques to maintain ecosystem services negatively affect the humid tropics. In this study, we focused on the mechanisms of GHG emissions, C storage, and their mitigation strategies. This review indicated technologies that can be adopted by farmers in humid tropics to maintain or increase their capacity to store C stocks and reduce GHG emissions. The adoption of climate-smart agriculture technologies and the regulation of ecosystem services markets will accelerate the progress of preserving the humid tropics. Improved management practices, such as proper N fertilizer management and the introduction of N2-fixing legumes, can increase soil C sequestration, providing economic and environmental trade-offs associated with these management strategies. Public and private investments toward knowledge dissemination and technology adoption regarding GHG emissions reduction and soil C storage are needed to allow humid tropics to maintain their critical function of generating environmental and societal benefits.

Biological Crusts to Increase Soil Carbon Sequestration: New Challenges in a New Environment.

The major priority of research in the present day is to conserve the environment by reducing GHG emissions. A proposed solution by an expert panel from 195 countries meeting at COP 21 was to increase global SOC stocks by 0.4% year-1 to compensate for GHG emissions, the '4 per 1000' agreement. In this context, the application of biocrusts is a promising framework with which to increase SOC and other soil functions in the soil-plant continuum. Despite the importance of biocrusts, their application to agriculture is limited due to: (1) competition with native microbiota, (2) difficulties in applying them on a large scale, (3) a lack of studies based on carbon (C) balance and suitable for model parameterization, and (4) a lack of studies evaluating the contribution of biocrust weathering to increase C sequestration. Considering these four challenges, we propose three perspectives for biocrust application: (1) natural microbiome engineering by a host plant, using biocrusts; (2) quantifying the contribution of biocrusts to C sequestration in soils; and (3) enhanced biocrust weathering to improve C sequestration. Thus, we focus this opinion article on new challenges by using the specialized microbiome of biocrusts to be applied in a new environment to counteract the negative effects of climate change.

Defining national biogenic methane targets: Implications for national food production & climate neutrality objectives.

Methane is a short-lived greenhouse gas (GHG) modelled distinctly from long-lived GHGs such as carbon dioxide and nitrous oxide to establish global emission budgets for climate stabilisation. The Paris Agreement requires a 24-47% reduction in global biogenic methane emissions by 2050. Separate treatment of methane in national climate policies will necessitate consideration of how global emission budgets compatible with climate stabilisation can be downscaled to national targets, but implications of different downscaling rules for national food production and climate neutrality objectives are poorly understood. This study addresses that knowledge gap by examining four methods to determine national methane quotas, and two methods of GHG aggregation (GWP100 and GWP*) across four countries with contrasting agriculture, forestry and other land use (AFOLU) sectors and socio-economic contexts (Brazil, France, India and Ireland). Implications for production of methane-intensive food (milk, meat, eggs and rice) in 2050 and national AFOLU climate neutrality targets are explored. It is assumed that methane quotas are always filled by food production where sufficient land is available. Global methane budgets for 1.5 °C scenarios are downscaled to national quotas based on: grand-parenting (equal percentage reductions across countries); equity (equal per capita emissions); ability (emission reductions proportionate to GDP); animal protein security (emissions proportionate to animal protein production in 2010). The choice of allocation method changes national methane quotas by a factor of between 1.7 (India) and 6.7 (Ireland). Despite projected reductions in emission-intensities, livestock production would need to decrease across all countries except India to comply with quotas under all but the most optimistic sustainable intensification scenarios. The extent of potential afforestation on land spared from livestock production is decisive in achieving climate neutrality. Brazil and Ireland could maintain some degree of milk and beef export whilst achieving territorial climate neutrality, but scenarios that comply with climate neutrality in India produce only circa 30% of national calorie and protein requirements via rice and livestock. The downscaling of global methane budgets into national policy targets in an equitable and internationally acceptable manner will require simultaneous consideration of the interconnected priorities of food security and (land banks available for) carbon offsetting.

Environmental impact of primary beef production chain in Colombia: Carbon footprint, non-renewable energy and land use using Life Cycle Assessment.

In Colombia, the beef production chain accounts for approximately 11.6 million cattle heads and annually produces 933 million kg of the beef carcass. There are no life cycle assessment (LCA) studies that have evaluated the environmental performance of Colombian beef systems. The present study aimed to estimate the carbon footprint (CF), non-renewable energy use, and land use of 251 cow-calf and 275 fattening farms in Colombia. The study also aimed to identify the main hotspots of adverse environmental impacts and propose possible mitigation options and their cost-effectiveness. The impact categories were estimated using the 2006 IPCC and the 2019 Refinement to 2006 IPCC guidelines, databases, and locally estimated emission factors. The functional units used were 1 kg fat and protein corrected milk (FPCM) and 1 kg live weight gain (LWG), leaving the farm gate. Three methods of allocating environmental burdens to meat and milk products were applied: economic, energy, and mass allocation. The adoption of improved pastures was considered a mitigation measure, and an economic assessment was performed to estimate the relative cost-effectiveness of its establishment. A principal component multivariate analysis and a Hierarchical Clustering on Principal Components were performed. The economic allocation method assigned a greater environmental burden to meat (83%), followed by energy content (80%) and mass production (73%). The largest sources of GHG emissions were enteric fermentation and manure deposited on pasture. Both cow-calf and fattening systems had a cluster of farms with better productivity, pasture and cattle management practices, and environmental performance. The CF for meat could be reduced by 33 to 56% for cow-calf and 21 to 25% for fattening farms, by adopting improved pastures. Therefore, our results suggest that GHG emissions can be reduced by adopting improved pastures, better agricultural management practices, efficient fertilizer usage, using the optimal stocking rate, and increasing productivity.

Assessing the eco-effectiveness of a solid waste management plan using agent-based modelling.

Municipal Solid Waste Management is yet to be eco-effectively performed, especially in developing countries. In Brazil, a considerable fraction of waste has been improperly landfilled, generating environmental, social and economic problems. In 2018, the government of the state of Paraná released a revised version of its waste management plan, defining improvement strategies to be gradually implemented until 2038. However, these strategies' eco-effectiveness has not been forecasted, nor the plan was deployed to the regional level. This research aims to fill this gap, downscaling the plan to the region of Norte Pioneiro, simulating its implementation and monitoring environmental and economic benefits. The dynamics of waste generation, collection and disposal are investigated using an agent-based model, considering the four population growth scenarios addressed in the plan. Targets for strategies of waste reduction, collection, source-separation and charging of waste fees are modelled. Multiple simulation runs were performed and outputs assessed and discussed. Results show that, if the plan is thoroughly implemented since 2020, at least 650 kilotons of avoided CO2eq emissions and US$ 40 million in avoided expenditures can be achieved in the most conservative scenario by 2038. Implications from the strategies proposed in the plan are highlighted, and recommendations to improve the plan's eco-effectiveness are outlined.

Environmental and anthropogenic drivers of soil methane fluxes in forests: Global patterns and among-biomes differences.

Forest soils are the most important terrestrial sink of atmospheric methane (CH4 ). Climatic, soil and anthropogenic drivers affect CH4 fluxes, but it is poorly known the relative weight of each driver and whether all drivers have similar effects across forest biomes. We compiled a database of 478 in situ estimations of CH4 fluxes in forest soils from 191 peer-reviewed studies. All forest biomes (boreal, temperate, tropical and subtropical) but savannahs act on average as CH4 sinks, which presented positive fluxes in 65% of the sites. Mixed effects models showed that combined climatic and edaphic variables had the best support, but anthropogenic factors did not have a significant effect on CH4 fluxes at global scale. This model explained only 19% of the variance in soil CH4 flux which decreased with declines in precipitation and increases in temperature, and with increases in soil organic carbon, bulk density and soil acidification. The effects of these drivers were inconsistent across biomes, increasing the model explanation of observed variance to 34% when the drivers have a different slope for each biome. Despite this limited explanatory value which could be related to the use of soil variables calculated at coarse scale (~1 km), our study shows that soil CH4 fluxes in forests are determined by different environmental variables in different biomes. The most sensitive system to all studied drivers were the temperate forests, while boreal forests were insensitive to climatic variables, but highly sensitive to edaphic factors. Subtropical forests and savannahs responded similarly to climatic variables, but differed in their response to soil factors. Our results suggest that the increase in temperature predicted in the framework of climate change would promote CH4 emission (or reduce CH4 sink) in subtropical and savannah forests, have no influence in boreal and temperate forests and promote uptake in tropical forests.

Spatial and temporal variability of soil N2 O and CH4 fluxes along a degradation gradient in a palm swamp peat forest in the Peruvian Amazon.

Mauritia flexuosa palm swamp, the prevailing Peruvian Amazon peatland ecosystem, is extensively threatened by degradation. The unsustainable practice of cutting whole palms for fruit extraction modifies forest's structure and composition and eventually alters peat-derived greenhouse gas (GHG) emissions. We evaluated the spatiotemporal variability of soil N2 O and CH4 fluxes and environmental controls along a palm swamp degradation gradient formed by one undegraded site (Intact), one moderately degraded site (mDeg) and one heavily degraded site (hDeg). Microscale variability differentiated hummocks supporting live or cut palms from surrounding hollows. Macroscale analysis considered structural changes in vegetation and soil microtopography as impacted by degradation. Variables were monitored monthly over 3 years to evaluate intra- and inter-annual variability. Degradation induced microscale changes in N2 O and CH4 emission trends and controls. Site-scale average annual CH4 emissions were similar along the degradation gradient (225.6 ± 50.7, 160.5 ± 65.9 and 169.4 ± 20.7 kg C ha-1  year-1 at the Intact, mDeg and hDeg sites, respectively). Site-scale average annual N2 O emissions (kg N ha-1  year-1 ) were lower at the mDeg site (0.5 ± 0.1) than at the Intact (1.3 ± 0.6) and hDeg sites (1.1 ± 0.4), but the difference seemed linked to heterogeneous fluctuations in soil water-filled pore space (WFPS) along the forest complex rather than to degradation. Monthly and annual emissions were mainly controlled by variations in WFPS, water table level (WT) and net nitrification for N2 O; WT, air temperature and net nitrification for CH4 . Site-scale N2 O emissions remained steady over years, whereas CH4 emissions rose exponentially with increased precipitation. While the minor impact of degradation on palm swamp peatland N2 O and CH4 fluxes should be tested elsewhere, the evidenced large and variable CH4 emissions and significant N2 O emissions call for improved modeling of GHG dynamics in tropical peatlands to test their response to climate changes.

Life cycle assessment of bagasse fiber reinforced biocomposites.

This study aims to evaluate the life cycle environmental implications of producing fiber-reinforced biocomposite pellets, compared with sugarcane- and petroleum-based polyethylene (PE) pellets. Life Cycle Assessment (LCA) methodology is used to evaluate the production of four types of pellets. LCA allows the evaluation of the benefits of improving the production of biobased materials by replacing part of the sugarcane bioPE with bagasse fibers. The functional unit selected was the production of 1 kg of plastic pellets. Primary data were collected from laboratory tests designed to obtain pulp fibers from bagasse and mix them with sugarcane bioPE. Two processes were studied to obtain fibers from bagasse: soda fractionation and hot water-soda fractionation. The results from the LCA show environmental improvements when reducing the amount of bioPE by replacing it with bagasse fibers in the categories of global warming, ozone formation, terrestrial acidification and fossil resource scarcity, when comparing to 100% sugarcane bioPE, and a reduction in global warming and fossil resource scarcity when compared to fossil-based PE. In contrast, results also indicate that there could be higher impacts in terms of ozone formation, freshwater eutrophication, and terrestrial acidification. Even though biocomposites result as a preferred option to bioPE, several challenges need to be overcome before a final recommendation is placed. The sensitivity analysis showed the importance of the energy source on the impacts of the processing of fibers. Thus, using clean energy to produce biobased materials may reduce the impacts related to the production stage. These results are intended to increase the attention of the revalorization of these residues and their application to generate more advanced materials. Further outlook should also consider a deeper evaluation of the impacts during the production of a plastic object and possible effects of the biobased materials during final disposal.

Environmental impacts of introducing cable cars in the Andean landscape: A case study for Kuelap, Peru.

Cable cars have slowly become a popular means of transport beyond their classical use at ski resorts. In Latin America their use has thrived to access archaeological sites in the Andes, but also in urban environments for mass transit. Despite some apparent benefits of these systems, the current literature is scarce in terms of quantifying the environmental profile of cable cars. Hence, their environmental performance as compared to other means of transport remains essentially unexplored. Therefore, the main objective of this study was to provide a comparative environmental analysis, using Life Cycle Assessment (LCA) methodology, of the two existing transport methods to visit the Kuelap Archaeological Complex, in northern Peru: a recently built cableway system and the alternative unpaved winding road. An attributional LCA perspective was performed for several impact categories, including global warming and particulate matter formation. In addition, a scenario analysis and an uncertainty analysis, using Monte Carlo simulation, were conducted to account for deterministic and stochastic results interpretation. Results demonstrated that succulent environmental benefits are attained when cable cars substitute road transport in complex Andean orographic conditions. However, the rebound effects of reducing traveling times significantly, as well as social and biodiversity aspects, should be analyzed in further depth to complement the environmental analysis.