Search Results (2,402)

Mining (1) operations in remote areas (2) face significant challenges related to energy supply, high fuel costs, and limited infrastructure. This study investigates the potential for achieving energy independence (3) and resilience (4) in such environments through the integration of renewable energy sources (5) and battery–electric mining equipment. Using the “Studena Vrila” underground bauxite mine as a case study, a comprehensive techno-economic and environmental analysis was conducted across three development models. These models explore incremental scenarios of solar and wind energy adoption combined with electrification of mobile machinery. The methodology includes calculating levelized cost of energy (LCOE), return on investment (ROI), and greenhouse gas (GHG) reductions under each scenario. Results demonstrate that a full transition to RES and electric machinery can reduce diesel consumption by 100%, achieve annual savings of EUR 149,814, and cut GHG emissions by over 1.7 million kg CO₂-eq. While initial capital costs are high, all models yield a positive Net Present Value (NPV), confirming long-term economic viability. This research provides a replicable framework for decarbonizing mining operations in off-grid and infrastructure-limited regions. Full article

Urban forests are vital to cities because they provide a range of ecosystem services, including carbon (C) sequestration, air purification, and urban cooling. However, urban forestry also generates significant amounts of organic waste, such as grass clippings, pruned tree branches, and fallen tree leaves and woody debris that can contribute to greenhouse gas (GHG) emissions if not properly managed. In this study, we investigated the effect of wheat straw biochar (produced at 500 °C) on GHG emissions from two types of urban forestry waste: green waste (GW) and yard waste (YW), using a 100-day laboratory incubation experiment. Overall, GW released more CO₂ than YW, but biochar addition reduced cumulative CO₂ emissions by 9.8% in GW and by 17.6% in YW. However, biochar increased CH₄ emissions from GW and reduced the CH₄ sink strength of YW. Biochar also had contrasting effects on N₂O emissions, increasing them by 94.3% in GW but decreasing them by 61.4% in YW. Consequently, the highest global warming potential was observed in biochar-amended GW (125.3 g CO₂-eq kg⁻¹). Our findings emphasize that the effect of biochar on GHG emissions varies with waste type and suggest that selecting appropriate biochar types is critical for mitigating GHG emissions from urban forestry waste. Full article

Hydrotreated ester and fatty acids to jet (HEFA-tJ) is presently the most developed and economically attractive pathway to produce sustainable aviation fuel (SAF). An ongoing systematic study of the critical variables of different pathways to SAF has revealed significantly lower greenhouse gas (GHG) reduction potential for the HEFA-tJ pathway compared to competing markets using the same resources for road diesel production. Moderate yield variations between air and road pathways lead to several hundred thousand tons less GHG reduction per project, which is generally not evaluated thoroughly in standard environmental assessments. This work demonstrates that, although the HEFA-tJ market seems to have more attractive features than biodiesel/renewable diesel, considerable viability risks might manifest as HEFA-tJ fuel market integration rises. The need for more transparent data and effort in this regard, before envisaging making decisions regarding the volume of HEFA-tJ production, is emphasized. Overall, reducing the carbon intensity of road diesel appears to be less capital-intensive, less risky, and several times more efficient in reducing GHG emissions. Full article

The sharing economy is considered to be a potentially efficacious approach for promoting sustainable production and consumption (SPC). This study utilizes dockless bike sharing (DBS) in Beijing as a case study to examine how sharing economy policies and business practices advance SPC. It also dynamically quantifies the environmental and economic performance of DBS practices from a life cycle perspective. The findings indicate that effective SPC practices can be achieved through the collaborative efforts of multiple stakeholders, including the government, operators, manufacturers, consumers, recycling agencies, and other business partners, supported by regulatory systems and advanced technologies. The SPC practices markedly improved the sustainability of DBS promotion in Beijing. This is evidenced by the increase in greenhouse gas (GHG) emission reduction benefits, which have risen from approximately 35.81 g CO₂-eq to 124.40 g CO₂-eq per kilometer of DBS travel. Considering changes in private bicycle ownership, this value could reach approximately 150.60 g CO₂-eq. Although the economic performance of DBS operators has also improved, it remains challenging to achieve profitability, even when considering the economic value of the emission reduction benefits. In certain scenarios, DBS can maximize profits by optimizing fleet size and efficiency, without compromising the benefits of emission reductions. The framework of stakeholder interaction proposed in this study and the results of empirical analysis not only assist regulators, businesses, and the public in better understanding and promoting sustainable production and consumption practices in the sharing economy but also provide valuable insights for achieving a win-win situation of platform profitability and environmental benefits in the SPC practice process. Full article

As the world’s largest developing and carbon-emitting country, China is accelerating its greenhouse gas (GHG) emission reduction process, and it is of vital importance in achieving the goals set out in the Paris Agreement. This paper examines the historical development and current operation of China’s carbon emissions trading market (CETM). The current progress of research on the implementation of carbon emissions trading policy (CETP) is described in four dimensions: environment, economy, innovation, and society. The results show that CETP generates clear environmental and social benefits but exhibits mixed economic and innovation effects. Furthermore, this paper analyses the challenges of China’s carbon market, including the green paradox, the low carbon price, the imperfections in cap setting and allocation of allowances, the small scope of coverage, and the weakness of the legal supervision system. Ultimately, this paper proposes recommendations for fostering China’s CETM with the anticipation of offering a comprehensive outlook for future research. Full article

In response to the escalating climate crisis, reducing greenhouse gas emissions (GHG) has become a top priority for both the public and private sectors. The pavement industry plays a key role in this transition, offering innovative technologies that minimize environmental impacts without compromising performance. Among these, the incorporation of recycled tire rubber and warm-mix asphalt (WMA) additives represents a promising strategy to reduce energy consumption and resource depletion in road construction. This study conducts a comparative life cycle assessment (LCA) to evaluate the environmental performance of an asphalt pavement incorporating recycled rubber and a WMA additive—referred to as R-W asphalt—against a conventional hot-mix asphalt (HMA) pavement. The analysis follows the ISO 14040/44 standards, covering material production, transport, construction, and maintenance. Two service-life scenarios are considered: one assuming equivalent durability and another with a five-year extension for the R-W pavement. The results demonstrate environmental impact reductions of up to 57%, with average savings ranging from 32% to 52% across key impact categories such as climate change, land use, and resource use. These benefits are primarily attributed to lower production temperatures and extended maintenance intervals. The findings underscore the potential of R-W asphalt as a cleaner engineering solution aligned with circular economy principles and climate mitigation goals. Full article

Electricity is a significant factor in the life cycle of many products, so the reliability of greenhouse gas (GHG) emissions data is crucial. The article presents publicly available sources of emission factors representative of Poland. The aim of the study is to assess their strengths and weaknesses in the context of the calculation requirements of carbon footprint analysis in accordance with the GHG Protocol. The article presents the results of carbon footprint calculations for different ranges of emissions in the life cycle of 1 kWh of electricity delivered to a hypothetical organization. Next, a discussion on the quality of the emissions factors has been provided, taking account of data quality indicators. It was concluded that two of the emissions factors that are compared—those based on the national consumption mix and the residual mix for Poland—have been recognized as suitable for use in carbon footprint calculations. Beyond the calculation results, the research highlights the significance of the impact of the selection of emissions factors on the reliability of environmental analysis. The article identifies methodological challenges, including the risk of double counting, limited transparency, methodological inconsistency, and low correlation of data with specific locations and technologies. The insights presented contribute to improving the robustness of carbon footprint calculations. Full article

The production of iron and steel plays a significant role in the anthropogenic carbon footprint, accounting for 7% of global GHG emissions. In the context of CO₂ mitigation, the steelmaking industry is looking to potentially replace traditional carbon-based ironmaking processes with hydrogen-based direct reduction of iron ore in shaft furnaces. Before industrialization, detailed modeling and parametric studies were needed to determine the proper operating parameters of this promising technology. The modeling approach selected here was to complement REDUCTOR, a detailed finite-volume model of the shaft furnace, which can simulate the gas and solid flows, heat transfers and reaction kinetics throughout the reactor, with an extension that describes the whole gas circuit of the direct reduction plant, including the top gas recycling set up and the fresh hydrogen production. Innovative strategies (such as the redirection of part of the bustle gas to a cooling inlet, the use of high nitrogen content in the gas, and the introduction of a hot solid burden) were investigated, and their effects on furnace operation (gas utilization degree and total energy consumption) were studied with a constant metallization target of 94%. It has also been demonstrated that complete metallization can be achieved at little expense. These strategies can improve the thermochemical state of the furnace and lead to different energy requirements. Full article

Efficient plastic waste end-of-life management is a serious worldwide environmental issue motivated by growing waste production and negative effects of wrongful disposal. This study presents a comparative overview of plastic waste management regimes within the European Union (EU), the United States of America (USA), and Romania, ranked with circular economy goals. By using the United States Environmental Protection Agency (US EPA) Waste Reduction Model (WARM), version 16, the study provides a quantified score to greenhouse gas (GHG) emissions within three large options of management: recycling, energy recovery through combustion, and landfilling. The model setup utilizes region-specific information on legislation, base technology, and recycling efficiency. The outcomes show that recycling always entails net GHG emissions reductions, i.e., −4.49 kg CO_2e/capita/year for EU plastic waste and −20 kg CO_2e/capita/year for USA plastic waste. Combustion and landfilling have positive net emissions from 1.76 to 14.24 kg CO_2e/capita/year. Economic indicators derived from the model also show significant variation: salaries for PET management amounted to USD 2.87 billion in the EU and USD 377 million in the USA, and tax collection was USD 506 million and USD 2.01 billion, respectively. The conclusions highlight the wider environmental and socioeconomic benefits of recycling and reinforce its status as a cornerstone of circular-economy sustainable plastic waste management and a strategic element of national development agendas, with special reference to Romania’s national agenda. Full article

Climate change mitigation Official Development Assistance (ODA) primarily aims to reduce greenhouse gas (GHG) emissions in developing countries while also seeking to enhance human welfare as a fundamental goal of development aid. This study investigates whether climate mitigation ODA contributes to achieving the principles of the doughnut framework—staying within the ecological ceiling (mitigating GHG emissions) while meeting the social foundation (enhancing human development index, HDI). We analyzed data from 77 developing countries between 2010 and 2020, including subgroup analyses by income level (high-, middle-, and low-income groups), using an instrumental variable–fixed effect approach. The results show that climate change mitigation ODA significantly improved the HDI but had no impact on reducing overall GHG emissions, including fossil fuel-based and land use change and forestry-based mitigations. When disaggregated by income level, ODA was found to improve the HDI and reduce fossil fuel-based GHG emission in low-income countries; however, these effects weakened as income levels increased. Across all income groups, there was no significant reduction in GHG emissions resulting from land use change or forestry. These findings suggest that climate change mitigation ODA can yield a greater impact when prioritized for low-income countries and that current ODA strategies for addressing GHG emissions related to land use change and forestry should be reconsidered. Full article

The environmental impact of milk production, particularly its share of greenhouse gas (GHG) emissions, is a topic under investigation in various parts of the world. This paper presents an overview of current knowledge on the carbon footprint (CF) of milk production at the farm level, with a particular focus on technological, environmental and organisational factors affecting emission levels. The analysis is based on a review of, inter alia, 46 peer-reviewed publications and 11 environmental reports, legal acts and databases concerning the CF in different regions and under various production systems. This study identifies the main sources of emissions, including enteric fermentation, manure management, and the production and use of feed and fertiliser. It also demonstrates the significant variability of the CF values, which range, on average, from 0.78 to 3.20 kg CO₂ eq kg⁻¹ of milk, determined by the farm scale, nutritional strategies, local environmental and economic determinants, and the methodology applied. Moreover, this study stresses that higher production efficiency and integrated farm management could reduce the CF per milk unit, with further intensification having, however, diminishing effects. The application of life cycle assessment (LCA) methods is essential for a reliable assessment and comparison of the CF between systems. Ultimately, an effective CF reduction requires a comprehensive approach that combines improved nutritional practices, efficient use of resources, and implementation of technological innovations adjusted to regional and farm-specific determinants. The solutions presented in this paper may serve as guidelines for practitioners and decision-makers with regard to reducing GHG emissions. Full article

Vehicle emissions, as a source of air pollution and greenhouse gases, have a significant impact on the environment and climate change. Battery electric vehicles (BEVs) have the potential to reduce air pollution and GHGs. However, BEVs often attract the criticism that their benefits are minimal as the power plant emissions compensate for emissions from the tailpipes of vehicles. This study compared two scenarios: scenario A considers all vehicles as internal combustion engine vehicles (ICEVs), and scenario B considers all vehicles as BEVs. The study used the City of San Antonio, Texas, as the study area. The study also focused on the seasonal and spatial variation in ICEV emissions. The results indicate that scenario A has a considerably higher volume of emissions than scenario B. For ICEVs, PM2.5 emissions were up to 50% higher in rural areas than urban areas, but 45% lower for unrestricted versus restricted conditions. CO₂ emissions were highly affected by seasonal variations, with a 51% decrease from winter to summer. The full adoption of BEVs could reduce CO₂ and N₂O emissions by 99% and 58% per km, especially for natural gas power resources. Therefore, BEVs play a significant role in reducing emissions from the transportation sector. Full article

The objective of this analysis was to compare the greenhouse gas (GHG) emissions from contemporary grazing cattle production with bison grazing, both modern and historical. The data sets used in this analysis were derived from existing research and conservation properties located outside of Manhattan, KS (USA), which are home to stocker cattle, cow–calf production (CCS), and grazing bison. For stocker cattle, 10 years of animal production data (2007–2016) from season-long stocking (SLS, grazing 156 d) and intensive early stocking systems (IES; 76 grazing d and 2× stocking density) were used for GHG calculations. Enteric CH₄, manure CH₄, and direct nitrous oxide emissions were estimated using the IPCC tier 2 methodology. Historic bison (HGB) enteric CH₄ estimates were calculated using a stocking density of 0.15 ha/animal and assuming that only 13% of grassland was used by bison each year. Within contemporary systems, IES had the lowest emissions (463.3 kg CO₂-eq./ha/yr), while SLS, CCS, and MGB had the highest estimates (494.7, 493.9, and 595.9 kg CO₂-eq./ha/yr, respectively). HGB had the lowest estimated annual emissions at 295.7 kg CO₂-eq./ha/yr. These results imply that the historic grazing baseline of this grassland system is lower but similar to that of contemporary grazing cattle in the Great Plains region. Full article

Soil organic nitrogen (SON) positively influences crop productivity, greenhouse gas (GHG) emissions, and sustained nitrogen (N) supply. Herein, we observed the effect of different treatments; no fertilizers (CK), chemical fertilizers (nitrogen, phosphorus, and potassium (NPK)), organic manure, and NPK + OM (NPKOM). This study was performed in a randomized complete block design (RCBD) with three replications. The results indicated that NPKOM treatment significantly decreased the nitrous oxide (N₂O) emissions by 19.97% and 17.47% compared to NPK in both years. This was linked with improved soil nutrient availability, soil organic carbon, soil organic nitrogen (SON) storage (10.06% and 12.38%), SON sequestration (150% and 140%), increased soil particulate (44.11% and 44%), and mineral-associated organic N (26.98% and 26.47%) availability. Furthermore, NPKOM also enhanced nitrate reductase (NR: 130% and 112%), glutamine synthetase (GS: 93% and 88%), sucrose phosphate synthase (SPS: 79% and 98%), SSs (synthetic direction; 57% and 50%), and decreased SSs activity in the decomposition direction (18% and 21%). This, in turn, inhibited the decomposition of sucrase and enhanced starch conversion into carbohydrates, thus leading to an increase in rice yield and a decrease in N₂O emissions. All fertilizations, particularly NPKOM, significantly enhanced grain protein contents by increasing N uptake and its availability. Therefore, NPKOM is an effective practice to enhance rice productivity, and SON sequestration and mitigate the N₂O emissions and subsequent climate change. Full article

The ameliorative mechanism of biochar in reducing soil greenhouse gas emissions in arid saline farmland remains unclear. A two-year field study in sorghum farmland in China’s Hetao Irrigation District was conducted to assess the influence of corn straw-derived biochar on GHG emissions and explore the role of soil physicochemical properties in regulating GHG fluxes. Four different biochar application rates were tested: 0 (CK), 15 (C15), 30 (C30), and 45 t hm⁻² (C45). Compared to CK, C15 reduced CH₄ emissions by 15.2% and seasonal CH₄ flux by 77.0%. The N₂O flux followed CK > C45 > C30 > C15 from 2021 to 2022. C15 and C30 significantly decreased GWP, mitigating GHG emission intensity. Biochar application enhanced sorghum grain yield. Soil temperature was the primary determinant of CH₄ flux (total effect = 0.92). In the second year, biochar’s influence on CH₄ emissions increased by 0.76. Multivariate SEM identified soil moisture (total effect = −0.72) and soil temperature (total effect = −0.70) as primary negative regulators of N₂O fluxes. C40 lead to salt accumulation, which increases CH₄ emissions but inhibits N₂O emissions. Averaged over two years, GWP under C15 and C30 decreased by 76.5–106.7% and 5.3–56.1%, respectively, compared to CK. Overall, the application of biochar at a rate of 15 t hm⁻² significantly reduced CH₄ and N₂O emissions and increased sorghum yield. Full article