Search Results (3,646)

The large-scale use of compost in arable cropping systems is often limited by the large quantities required to meet the crop’s nutritional needs. Palletization can increase the nutrient density of organic fertilizers and improve their logistical feasibility by reducing storage, transport and application costs. This study evaluated the agronomic and environmental performance of compost pellets derived from pig slurry solids and olive pomace, using them as an alternative nitrogen source for wheat (Triticum aestivum L.) cultivated under Mediterranean conditions. A field experiment was conducted during the 2022–2023 growing season, with four treatments arranged in 24 m² replicated plots: an unfertilized control (C); pelletized compost (PSCOP); fresh pig slurry (PS); and mineral fertilization based on monoammonium phosphate and urea (IN). Excluding the control treatment, all fertilized plots received a uniform nitrogen rate of 150 kg N ha⁻¹. Soil chemical properties and nutrient availability (Pext, NH₄⁺-N and NO₃⁻-N) were evaluated at the beginning and end of the experiment, while wheat yield and grain quality were assessed at harvest. Greenhouse gas (GHG) emissions were monitored throughout the cropping season to evaluate environmental impacts. The results showed that the wheat yields achieved with PSCOP were comparable to those obtained with PS, although they remained lower than those achieved with mineral fertilization. Grain quality was not adversely affected by the application of PSCOP. Furthermore, PSCOP resulted in lower GHG emissions than mineral fertilization, with values closer to those observed in the unfertilized control. These findings suggest that pelletized organic fertilizers such as PSCOP may be a promising way to enhance nutrient circularity and reduce reliance on synthetic fertilizers and maintain crop productivity and limit environmental impact in Mediterranean agricultural systems. Full article

The production and use of plastics have direct consequences on the environment, such as the greenhouse gas emissions (GHGs) they cause. Therefore, it is necessary to develop materials from renewable sources with a lower environmental impact to replace plastic. In this work, films with bioactive properties have been developed from cellulose nanofibers (CNFs) and natural phenolic compounds for food packaging applications. First, the optimization of the incorporation of three different natural phenolic compounds (tannic acid, p-coumaric acid, and acetosyringone) into nanocellulose was studied using a Box–Behnken design, with the phenols adsorbed by the nanocellulose as the output variable. Once the incorporation was optimized, films containing nanocellulose and phenolic compounds were produced and characterized. Tannic acid showed the best results with regard to the optical properties of the resulting films and achieved a complete blocking of UV-B radiation, as well as adding to nanocellulose antioxidant (4.32 mM TE/g film) and antibacterial capacity (log R of 6.6 ± 0.2 and 3.8 ± 0.1 for Staphylococcus aureus and Escherichia coli, respectively), making these films a promising material for use in contact with food as a packaging material, although more in-depth studies and measures are needed to make these films viable for use in food packaging. Full article

Greenhouse gas (GHG) emissions are one of the leading environmental concerns faced nowadays. The chemical looping combustion (CLC) process is one of the main processes that aim for carbon capture, utilization, and storage (CCUS), allowing the generation of a high-purity CO₂ stream that can be easily captured. Brazil has a wide variety of biomasses that could be applied to CLC, and the behavior of these biomasses can be predicted using machine learning algorithms. An artificial neural network (ANN) was created considering the biomass characteristics (proximate and ultimate analysis) and fuel reactor temperature as input data to assess their influence on CLC performance parameters (carbon capture efficiency, η_CC, and total oxygen demand, Ω_T) and gas compositions. The characteristics of five Brazilian biomasses were considered in the constructed ANN to predict their behavior on CLC performance. The ANN presented a good data fit, with R² achieving values higher than 0.973. Volatile matter played a crucial role in predicting the CLC performance parameters. Rice husks presented the smoothest results for η_CC and Ω_T, while the CO₂ composition was most affected by the eucalyptus characteristics. Experimental tests with all the biomasses should be carried out to provide a higher prediction capability of the algorithm. Full article

Deep decarbonization strategies at the local level have been extensively documented for cities in the Global North, yet little is known about how cities in Sub-Saharan Africa (SSA) pursue climate mitigation amid infrastructure constraints, limited fiscal autonomy, and pressing developmental needs. Local governments worldwide are recognized as critical actors in addressing urban greenhouse gas (GHG) emissions. However, SSA cities’ decarbonization efforts remain underexplored in academic and policy discourse, despite the region’s acute climate vulnerability and rapid urbanization. However, SSA cities’ decarbonization efforts remain underexplored in academic and policy discourse, despite the region’s acute climate vulnerability and rapid urbanization. This study examines how deep decarbonization pathways in four leading SSA cities (Accra, Addis Ababa, Lagos, and Nairobi) compare with those in the Global North. Using qualitative methods including document analysis and semi-structured interviews, we examine the technical pathways, institutional strategies, governance mechanisms, and actors involved in these cities’ climate mitigation efforts. Our findings reveal that while SSA cities pursue similar technical priorities to Global North cities (renewable energy, building efficiency, sustainable transport), their approaches diverge significantly in implementation. SSA cities innovate through decentralized waste-to-energy systems adapted to informal contexts, rely heavily on donor funding rather than municipal bonds, and uniquely leverage traditional institutions for community engagement. Governance structures are predominantly top-down and centralized, contrasting with the polycentric, multi-level governance observed in the Global North. These findings demonstrate that deep decarbonization in SSA must be reconceptualized not only as a form of climate mitigation but as an integrated strategy that addresses infrastructure gaps and building institutional capacity. This research contributes new knowledge on urban climate governance in developing regions and offers transferable lessons for cities facing similar constraints. Full article

The optimization of crop production in the context of agricultural land use and production inputs is a strategic element of sustainable development. Fertilization and irrigation are vital components of agricultural engineering, driving crop quantity and quality. The objective of the study discussed here was to assess greenhouse gas emissions from carrot cultivation depending on the variant of the fertilization and irrigation processes. One tonne of marketable carrot yield was selected as the functional unit. A controlled field experiment in a split-plot configuration was carried out to deliver the objective. Calculation of the total quantity of greenhouse gases emitted from the crop was carried out according to ISO 14040 and ISO 14044. Boundaries of the system encompassed the production and use of fertilizers and pesticides, the consumption of energy for agro-engineering activities and irrigation, as well as GHG emissions from soil resources and crop residue. The reference unit for the study was an object (plot) irrigated according to production practice in the area where the study was conducted. Under those conditions, greenhouse gas emissions totaled 75.68 kg CO² ⸱ t⁻¹ of the commercial product. Optimization, involving precise irrigation and fertilization using slow-release fertilizers, reduced the carbon footprint to 54.33 kg CO² ⸱ t⁻¹ of the commercial product. GHG emissions were thus reduced by 30%. The use of slow-release fertilizers resulted in a reduction of total greenhouse gas emissions per unit of marketable yield by 15% for non-irrigated crops and by 17% for irrigated crops. Irrigation, in turn, resulted in a reduction of total GHG emissions by 8% for conventional fertilization and by 11% for slow-release fertilization. Full article

The recent proliferation of electronic waste (E-waste) in developing countries has become a pressing environmental and socio-economic issue, particularly in urban areas where informal waste management practices dominate. The current E-waste collection system in Yaoundé comprises three streams: informal, formal, and municipal solid waste collection. However, transitioning to a prospective, integrated system requires optimizing E-waste collection. Given that the current formal collection (CFC) scenario has only 3 formal collection points, this study employs a survey-based approach and GIS network analysis to allocate 8 additional collection points to maximize formal collection coverage and quantity in Yaoundé. The applied methodologies included the consumer and use model and GIS-based location-allocation, service-area, and route-optimization analyses. The results indicate a 52.81% increase in formal collection quantity for the maximized formal collection (MFC) scenario. Furthermore, Route 1 proved to be the most cost-effective, with a fuel consumption cost of 806,472.25 FCFA/year. Additionally, Route 1 yielded the lowest GHG emissions, at 2610.32 kg CO₂ eq/year, compared with Routes 2 and 3. Finally, transitioning from the current business-as-usual (BAU) to a prospective integrated E-waste management (IEM) system resulted in a 13.83% potential reduction in emissions. This emission reduction contributed 3.04% to Cameroon’s nationally determined contributions (NDCs) 2030 target for greenhouse gas (GHG) emission reduction in the waste sector. The study’s outcome proves informative for decision-making in optimizing E-waste management systems in developing economies. Full article

Livestock production significantly contributes to greenhouse gas (GHG) emissions, particularly methane (CH₄) and nitrous oxide (N₂O) originating from enteric fermentation and manure management. This study quantified the GHG emissions and cumulative carbon footprint of four commercial sheep farms (SF1, SF2, SF3, and SF4) in the Bursa region of Türkiye, with flock sizes of 200, 500, 150, and 800 adult Merino sheep (mature ewes and breeding rams), respectively. Using the IPCC Tier 2 methodology, the biogenic carbon footprint was estimated at 15.6 kg CO₂-eq per kg of boneless sheep meat. However, when indirect inputs were included, the cumulative carbon footprint reached 28.8 kg CO₂-eq for ewes and 32.3 kg CO₂-eq for breeding rams. These results indicate that indirect emissions from feed production account for the primary environmental load (49.8%), while on-farm energy-related emissions represent a minor portion (0.3%) of the total impact. The results demonstrate that while enteric fermentation (32.5%) remains a critical biological factor, the environmental burden of the feed supply chain is equally significant in intensive systems. These findings highlight that excluding indirect inputs leads to a substantial underestimation of the climate impact, suggesting that mitigation strategies must integrate nutritional optimization with enteric methane reduction to decarbonize sheep production effectively. Full article

The limited existing studies elucidate the significant contribution of open dumpsites to greenhouse gas emissions in Sri Lanka and underscore the necessity of improved waste management practices. Considering this, this study formulates and implements a scenario-based transition framework to assess the potential for reducing greenhouse gas emissions by diverting biodegradable waste in a semi-urban governance setting in Sri Lanka, which is marked by data limitations and operational challenges. This study concludes that the environmental feasibility analysis reinforces the potential benefits of solid waste compost adoption in municipal solid waste management and agriculture. Greenhouse gas emissions (CO₂, CH₄, and N₂O) were analyzed using the IPCC Tier 1 methodology. The findings revealed that the total emissions declined significantly from 163.10 tonne CO₂ eq/month to 99.31 tonne CO₂ eq/month. The results indicate that diverting biodegradable waste to composting can play a crucial role in climate mitigation in semi-urban contexts, while promoting organic farming. These findings represent the first scenario-based GHG quantification in a semi-urban context in Sri Lanka, addressing a governance level that has received negligible attention in the composting and waste management literature. The scenario-based evaluation framework offers indicative guidance for municipalities in similarly constrained developing contexts, although direct applicability is contingent on comparable waste compositions, governance structures, and operational conditions. Full article

The escalating global production of plastics poses significant environmental challenges, such as greenhouse gas (GHG) emissions and widespread pollution. This review critically examines contemporary research on plastic sustainability strategies, focusing particularly on the circular economy (CE), end-of-life management, and emerging concepts such as offsetting. Despite various initiatives advocating the reduce–reuse–recycle (3Rs) approach, only 9–10% of plastic is effectively recycled, with substantial volumes incinerated or landfilled, exacerbating environmental degradation. Moreover, the review highlights geographic disparities, highlighting that regions with robust infrastructure achieve more effective waste management than developing areas. The adoption of bioplastics as sustainable alternatives remains limited due to their complex life cycle and production processes. This review synthesizes the CE, Life Cycle Assessment (LCA), and offsetting tools in the context of plastics towards the development of plastic offsetting strategies as a waste management solution. It identifies critical literature gaps, where existing plastic waste management systems are limited to affordability and geographical restrictions. The review highlights the various plastic circularity strategies and their limitations, while addressing carbon offsetting as an inspiration for a plastic offsetting mechanism that could significantly enhance global strategies to mitigate plastic pollution, particularly in developing regions, fostering more sustainable global waste management practices. Therefore, plastic offsetting, inspired by carbon offset mechanisms, emerges as a novel strategy that offers financial incentives by sponsoring plastic waste management projects to effectively managing plastic waste in less developed regions. Full article

A central goal of carbon (C) management and a critical outcome of sustainable land stewardship is reducing greenhouse gas (GHG) emissions from agriculture, forestry, and other land uses. Integrating GHG considerations into management can take many forms, but C credit markets are increasingly providing sources of private capital to offset the often high costs of stewardship. In Hawaiʻi, participation in voluntary C credit markets and the establishment of jurisdictional compliance C markets are constrained by a lack of institutional capacity, successful demonstrations, and high-quality data, making private capital for C market-based approaches in Hawaiʻi difficult to access. The State of Carbon in Hawaiʻi Hui (hui translates to partnership in ʻŌlelo Hawaiʻi, the Hawaiian language) convened landowners, researchers, federal and state government professionals, and for-profit and not-for-profit organization staff to better understand limitations to implementing C management in Hawaiʻi. This paper describes why the State of Carbon in Hawaiʻi Hui was formed, how we planned for, hosted, and assessed the success of a C-focused summit, and what outcomes resulted from this process. A Pathway Forward document, a decision support tool, and this article are outcomes. These products will serve as resources for those considering Hawaiʻi-based forest C projects, as well as contributing towards the legislated goal of reducing greenhouse gas emissions in Hawaiʻi. Our knowledge exchange process is readily replicable and can support a variety of efforts in environmental conservation and beyond. Full article

This study assesses long-term structural changes in greenhouse gas (GHG) intensity across 38 OECD member countries over the period of 2000–2020 using a multidimensional Z-score standardization framework. GHG intensity was measured using three activity-based indicators—emissions per unit of land area, per capita emissions, and emissions per unit GDP—which were then aggregated into a Composite GHG Intensity Score (GHGIS) to facilitate cross-country comparison while accounting for differences in territorial scale, demographic structure, and economic output. The results reveal substantial heterogeneity in both the level and trajectory of composite GHG intensity across OECD member states. Countries such as Sweden (ΔScore = −0.84) and Denmark (ΔScore = −0.67) demonstrated a decrease in GHGIS, reflecting relative improvements in emission efficiency, while Korea (ΔScore = +0.92) and Türkiye (ΔScore = +1.15) recorded positive shifts in relative positioning over the study period. Several countries, including the United Kingdom, Germany, Japan, and Israel, exhibited divergent trends across land-, population-, and GDP-based measures, highlighting the multidimensional nature of national emission structures. These findings demonstrate that relative changes in GHG intensity vary across structural dimensions and cannot be adequately characterized by single-indicator measures alone. While the analysis does not identify causal drivers of observed patterns, the standardized composite framework provides a transparent and replicable tool for examining long-term comparative shifts in multidimensional emission intensity. By applying a consistent methodology across all OECD member countries over two decades, the study contributes to comparative assessments of structural GHG intensity dynamics. Full article

To develop carbon farming practices, decision-makers need detailed spatial data on the soil carbon sequestration (SCS) opportunities that conventional crop and soil management creates. This study exploratorily assessed SCS capacity across agricultural land in the Valencian Community using a simple carbon balance model within a GIS framework. Within this modelling approach, maps of net primary production (NPP), land-use-derived crop harvest indices, current soil organic carbon (SOC) stocks, and NPP and SOC mineralization coefficients were combined. Results show that while NPP across Valencian croplands and grasslands ranges from 0.64 to 6.43 Mg C ha⁻¹ yr⁻¹ (mean 2.42 Mg C ha⁻¹ yr⁻¹), the actual SCS capacity is much lower, ranging from −0.04 to 1.31 Mg C ha⁻¹ yr⁻¹ (mean 0.25 Mg C ha⁻¹ yr⁻¹). Significant variation exists among land uses: rice paddies exhibit the highest SCS capacity, while olive groves present the lowest. Between 2017 and 2021, SCS in Valencian agroecosystems may have offset the sector’s greenhouse gas (GHG) emissions, primarily driven by pasture and citrus because of their large extent and moderate SCS capacity, making agriculture a net-zero emitter. However, helping achieve cross-sectoral mitigation targets will depend in part on the widespread deployment of regenerative soil management (RSM) practices. While this study identifies priority areas for RSM implementation, further research is needed to determine which specific practices are most suitable for each location to maximize SCS. Full article

Maritime transport is essential for global trade, yet ship emissions remain a major source of air pollution in coastal and port areas, with potential impacts on local air quality and human health. Cruise ships are particularly relevant in urban ports because, beyond propulsion, they require a continuous onboard energy supply for hotel services while berthed. This study develops a bottom-up emission inventory for cruise ship calls at Istanbul Galataport during the 2024 season, estimating CO₂ as a greenhouse gas (GHG) and NO_x, SO_x, and particulate matter (PM) as air-quality pollutants generated during manoeuvring and hotelling phases. Ship technical characteristics (engine type, installed main and auxiliary power, engine speed class, and year of build) were obtained from the IHS database, while port call activity data were provided by the terminal operator. Emission factors were primarily based on the IMO Third Greenhouse Gas Study and complemented with established literature sources to address missing vessel information and ensure methodological consistency. Results indicate that hotelling dominates total emissions, reflecting the high auxiliary power demand during berths. Results show that total annual emissions from 164 cruise ship calls amount to approximately 31,360 t·y⁻¹ of CO₂, 370 t·y⁻¹ of NO_x, 350 t·y⁻¹ of SO_x, and 44 t·y⁻¹ of PM. Hotelling operations account for the dominant share of emissions, contributing more than 90% of total CO₂ and the majority of NO_x and SO_x emissions, due to sustained auxiliary engine demand during berth stays. These findings confirm that cruise ship activity represents a significant localized emission source in densely populated port environments and provide a quantitative baseline for evaluating mitigation measures such as shore power, cleaner fuels, and operational strategies aimed at reducing at-berth emissions. Full article

Aviation remains one of the European Union’s most challenging sectors to decarbonize. The Circular Economy (CE) offers a systemic framework for reducing resource intensity and supporting sustainability transitions. Yet empirical evidence linking CE progress to aviation environmental outcomes remains scarce. This study examines 27 EU Member States between 2010 and 2024. We analyze how circularity performance, sustainability factors, and tourism-driven demand shape aviation greenhouse gas (GHG) emissions. Using fixed-effects panel models and causal mediation analysis, we find that CE progress enhances renewable energy adoption and resource productivity. However, CE has no direct effect on aviation emissions. Instead, tourism intensity, captured through air passenger volumes, emerges as the strongest and most consistent predictor of aviation GHG emissions. Aviation energy consumption mediates 76% of the relationship between tourism demand and aviation emissions through increased fuel use. The findings indicate a structural decoupling between macro-level CE policies and aviation emissions, highlighting the central role of energy use and demand growth in shaping aviation’s environmental impact. Full article

Livestock production systems are considered some of the most environmentally degrading due to greenhouse gas (GHG) emissions and their contribution to poor air, soil and water quality, amongst other impacts. Advanced manure treatment technologies are required in response to intensification of dairy production worldwide, and the considerably greater volumes of manure generated that require collection and management. Similarly, in Australian dairy systems cows spend more time off pasture, with increased collection of larger manure volumes from a range of contained housing facilities. Adoption of advanced treatment is required to capture nutrients at risk of loss, and ideally to valorise manure to support uptake of these technologies. This review describes the generation of manure and the manure sources found in commercial Australian systems, including grazing-based and intensive dairy farms, supporting zero grazing. The review draws on manure data from pasture-based industries elsewhere and summarises their properties for comparison with Australian systems. Manure treatments that recover and retain nutrients, water and energy are reviewed. These include additives, mechanical/chemical/membrane separation, thermochemical and biological treatments which produce organic and inorganic soil amendments, clarified or potable water, gases (N₂, H₂), biofuels and energy. The review describes the technical and operational details of the technologies, and where there are opportunities for the Australian dairy industry. Treatment technologies need to be validated for Australian systems based on the collated data of local manure properties, as differences with international manure data have been observed. The relative costs, technological maturity, and the benefits and challenges associated with adoption are discussed. Many advanced technologies are ready for adoption, but others are experimental or at pilot stage and relative costs range from low to very high. However, to accurately assess feasibility of manure treatments, environmental, and production benefits should be balanced against capital and operating expenses and account for costs associated with current management. For large intensive farms, implementing advanced manure technologies may be required to ensure approval to operate/expand and to meet regulatory compliance. Future research for the Australian industry should investigate nutrient retention and further develop separation treatments incorporating chemical and mechanical technologies. Bioconversion of manure through insect composting as well as investigating co-digestion opportunities to enhance biogas production would support famers currently using these systems. Full article