Search Results (563)

The mining industry is a cornerstone of global energy security and industrial supply chains, yet its resilience to systemic disruptions such as COVID-19 has been critically overlooked. This disruption provided a rare opportunity to trace supply-chain impacts. Using an environmentally extended multi-regional input-output (EEMRIO) model integrated with a Criteria Importance Through Intercriteria Correlation (CRITIC) weighted approach. We compare pandemic trajectories with counterfactual no-pandemic trajectories: the no-pandemic model (calibrated on 2004–2018) projects 2019–2025, while the pandemic model (calibrated through 2023) projects 2023–2025, with 2023 serving as the observed baseline and transition year. Our findings reveal a transient reduction in mining water and carbon footprints, juxtaposed with stark economic contractions: mining value fell by 40% in China, 37% in India, and 13% in the United States. The weighted component among the water-carbon-value (WVC) analysis further uncovers a tripolar spatial pattern, categorizing countries into financial hubs with high value, such as Switzerland, carbon-locked exporters like Brunei, and water-stressed regions, including Cambodia. Despite absorbing substantial embodied environmental burdens, China maintained its position as the global value hub. These insights underscore the urgency of policies that enhance structural efficiency, decarbonize the power sector, and foster supply chain diversification to decouple economic value from environmental pressures while mitigating spatial inequalities. Full article

The pursuit of sustainable development, particularly the mitigation of climate change (SDG 13), necessitates a thorough understanding of the environmental consequences of international trade. The form and pattern of international trade have changed with the rise of preferential trade agreements. The following important question arises: how do preferential trade agreements affect the transfer of trade-embodied carbon emissions? This study establishes a comprehensive bilateral trade database and uses a staggered difference-in-differences model to empirically examine how preferential trade agreements affect embodied carbon emissions. Furthermore, this study explores the underlying mechanisms and investigates heterogeneous effects in diverse contexts. The key findings of this study are as follows. (1) The signing of preferential trade agreements between bilateral trading partners helps reduce the level of carbon embodied in exports. (2) This reduction is achieved by improving production efficiency and facilitating technological spillovers, thereby reducing the carbon footprint associated with export activities. (3) The level of development of bilateral trading countries and the strength of environmental regulations play a role in the heterogeneous impact of preferential trade agreements on embodied carbon emissions. These findings provide critical empirical evidence for designing PTAs that not only facilitate trade but also actively contribute to global climate action and the achievement of broader sustainability objectives. Full article

Within the framework of the dual carbon strategy, investigating the spatiotemporal characteristics and driving factors of carbon sequestration in metropolitan areas through land use analysis is important for mitigating climate change and promoting regional ecological protection and sustainable development. On the basis of land use time points for five phases from the Jinan metropolitan area (JMA) covering the period from 2000 to 2024, the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model was coupled with the extreme gradient boosting (XGBoost)–Shapley Additive exPlanations (SHAP) and multiscale geographically weighted regression (MGWR) models to explore the spatiotemporal variations in carbon storage and its driving factors. In the last 24 years, cropland has been the predominant land use category in the JMA, representing almost 62% of the overall area. Throughout the five periods, the transition from cropland to construction land predominated, resulting in an 11.78% reduction in farmland and a 49.73% expansion in construction land. Between 2000 and 2024, carbon storage in the JMA decreased overall, with a total reduction of 3.70 Tg. The occupation of farmland for construction purposes was the primary cause of the decrease in carbon storage. The spatial pattern of carbon storage was similar to that of land use in the JMA, characterized by a distribution pattern with elevated values in the southeast and reduced values in the northwest. The SHAP analysis results demonstrated that the contributions of driving factors such as elevation, vegetation coverage, human footprint, and population density were generally high, making them the main drivers affecting carbon storage, with a significantly greater contribution of natural factors than human activity factors. The MGWR model results revealed that the digital elevation model and fractional vegetation cover positively influenced carbon storage in the JMA, whereas the population density imposed a negative effect. These results could guide the judicious allocation and utilisation of resources in urban regions, the establishment of ecological conservation areas, and the advancement of regional sustainability. Full article

Research Highlights: This study quantifies aboveground biomass for Oreopanax oroyanus and Escallonia resinosa in an Andean relict forest and examines their conservation relevance related to the scale of emissions voluntarily reported by small corporate emitters. Background and Objectives: Andean relict forests face severe fragmentation and degradation. This research evaluates carbon stocks in the Bosque de Zárate Reserved Zone (Peru) and explores how these findings may inform climate mitigation and conservation initiatives by examining their potential alignment with emissions voluntarily reported by Peruvian firms participating in a carbon disclosure system. Materials and Methods: A total of 27 plots were evaluated between 3034 and 3200 m a.s.l., tree height and diameter (DBH ≥ 10 cm) were measured for key species, and biomass was estimated using a pantropical allometric equation. Landsat imagery (1985–2025) was analyzed to assess long-term vegetation conditions, while Dynamic World land cover and Sentinel-1 radar (2018–2025) were used to assess forest cover and canopy structure changes. Voluntarily reported emissions of Peruvian firms participating in the “Carbon Footprint Peru” system (2012–2024) were analyzed to contextualize the forest results in the potential corporate interest in climate mitigation in Peru. Results: Total aboveground carbon stock for the altitudinal belt in the study area was 919.4 Mg C (18.6 Mg C ha⁻¹), equivalent to 3374.2 Mg CO₂, with Escallonia resinosa accounting for approximately 71% of the estimated stock. Multi-decadal satellite observations indicated persistent forest cover within the evaluated belt, while analysis of voluntarily reported corporate emissions identified numerous service-sector firms with annual emissions below 100 Mg CO₂ eq, providing context for the potential scale of future conservation-financing initiatives. Conclusions: Relict forests offer relevant localized carbon storage linked to other ecosystem services. Providing field-based carbon data may support the development of locally relevant community-led initiatives meaningful to climate-financing initiatives. However, the existing carbon stock does not by itself represent a source of carbon credits, and carbon capture-specific studies would need to be implemented to fully assess the mitigation capacity of these ecosystems. Full article

Methane emissions from coal mines pose significant environmental and operational challenges. Methane can be released from coal seams and surrounding rock layers as a result of mining operations. These emissions pose environmental risks and can lead to fire and explosion hazards. Therefore, reducing coal mine methane emissions is essential for both protecting miners’ safety and cutting greenhouse gas emissions. Additionally, capturing methane before it escapes into the atmosphere can be economically beneficial and used as a valuable energy source. This study proposes an integrated approach that combines advanced methane capture and hydrogen production technologies to enhance both environmental performance and energy recovery in coal mining operations. By combining methane capture with hydrogen production, the study presents a practical solution for lowering greenhouse gas emissions in the coal sector. This strategy promotes the adoption of low-carbon energy sources and offers a sustainable path forward for coal-dependent regions facing decarbonization challenges. A scenario-based techno-economic analysis is presented, including investment and operating costs, hydrogen yield, energy generation potential, and greenhouse gas mitigation. Further research should focus on process optimization, the integration of carbon capture technologies, and the valorization of by-products to further reduce the environmental footprint. Full article

Driven by global climate change and Taiwan’s Net-Zero initiatives, high-input livestock farming faces urgent pressures to transform. Pennisetum purpureum, a primary forage and bioenergy crop, traditionally relies on heavy chemical nitrogen inputs, thereby exacerbating its carbon footprint. This study evaluated a sustainable cultivation model integrating legume intercropping with reduced fertilization. A field trial in central Taiwan utilizing a Completely Randomized Design (CRD) compared four treatments: conventional full nitrogen (800 kg N/ha), sunn hemp (Crotalaria juncea) intercropping with half nitrogen, sunn hemp intercropping only, and organic compost. We monitored biomass, forage chemistry, and soil organic carbon (SOC) dynamics. The sunn hemp plus half-nitrogen treatment achieved dry matter yields (30–35 Mg/ha) and crude protein levels (7.1–7.4%) statistically equivalent to the full-nitrogen control, significantly surpassing other groups. While short-term SOC stocks (72–81 Mg C/ha) showed no significant differences, trends indicated carbon accumulation in deep soil (30–50 cm). Consequently, substituting 50% of chemical nitrogen through biological fixation proves a viable strategy to maintain yield while reducing inputs. This model sustains productivity and mitigates greenhouse gas emissions, offering an economically feasible, potential carbon-negative solution for tropical forage systems. Full article

Reducing the greenhouse gas (GHG) intensity of dairy production remains challenging because enteric methane and upstream supply chain emissions persist despite existing mitigation strategies. This study evaluated a supply chain decarbonization approach in which Spirulina (Arthospira platensis) produced through a carbon-removal supply chain (GeoSpirulina) was incorporated into dairy rations to enable net supply chain carbon removal within cradle-to-farm-gate boundaries. A carbon-focused life cycle assessment (LCA) was combined with a commercial-scale feeding trial to determine an appropriate inclusion rate and assess production outcomes. The LCA integrated primary activity and production data from the commercial dairy farm with previously published GeoSpirulina production and soil organic carbon sequestration data derived from primary Icelandic production and field studies, supplemented by secondary background datasets and published dairy emission estimates. GeoSpirulina was produced using geothermal energy and coupled with soil organic carbon sequestration associated with the application of residual biomass as a soil biostimulant, resulting in a modeled net-negative production footprint. Under the defined LCA assumptions, supplementation with 2 g cow⁻¹ day⁻¹ of GeoSpirulina reduced the modeled milk GHG intensity from approximately 1.9 to 0.06 kg CO₂e kg⁻¹ at the farm gate. Scenario analysis identified active vitamin B₁₂ concentration as a key driver of the modeled carbon balance. Milk yield and group-level feed efficiency were unaffected, whereas butterfat (+4.7%, p = 0.002), fatty acids (+4.4%, p = 0.011), and somatic cell count (−71%, p = 0.007) improved without detectable adverse effects. These findings suggest that carbon-negative feed ingredients may provide a complementary sustainability strategy for dairy production by embedding measurable carbon removal within agricultural supply chains while maintaining production performance. Although this approach counterbalances rather than eliminates biological emissions, it may contribute to broader dairy decarbonization and sustainable food-production strategies alongside direct greenhouse gas mitigation interventions. Full article

The dual reliance on surface-mount technology (SMT) and pin-through-hole (PTH) assembly lines in high-volume printed circuit board (PCB) manufacturing induces logistical bottlenecks, excessive operational costs, and elevated thermal stress on components. This study presents the optimization of a wireless detector terminal production line by integrating Pin-in-Paste (PiP) technology within a Six Sigma DMAIC (Define, Measure, Analyze, Improve, Control) framework. By accurately calculating the required solder volume ($V_{req}$) and stencil aperture dimensions based on pin and pad geometries, the wave soldering process was eliminated without altering existing thermal profiles. The integration consolidated the assembly into a single heat cycle, ensuring IPC-A-610 Class 2 compliance for barrel fill ratios. The results demonstrate a 97% reduction in average assembly costs, yielding annual savings of USD 92,513 while eliminating USD 44,025 in work-in-progress (WIP) inventory. Furthermore, the single-reflow approach mitigated component thermal degradation and reduced the facility’s carbon footprint by an estimated 13.32–17.76 metric tons of CO₂ equivalent annually. This research validates a comprehensive methodology for transitioning to PiP technology, offering a sustainable, cost-effective framework for operational excellence in the electronics’ manufacturing industry. Full article

The assimilation capacity of the biosphere and the sustainability of the living resources are enhanced by the efficient and continued contribution of the vegetation from all ecoregions of the Earth. The urban greenery fulfills many regulatory ecosystem services (RES) as well. In this regard, the importance of urban green spaces (UGS) in helping to reduce the adverse impacts of overcrowding and changing climate is of pertinence. Lack of quantitative information from urban settings in different climatic regions seriously constrains the recognition of the important role UGS play in carbon storage and sequestration. To assess how the UGS is aiding the retention of carbon, which is photosynthetically assimilated into biomass and/or sequestered, relevant field parameters were collected from 4010 trees belonging to 34 different species, different hedge plants, and groundcover grasses spread in 24,991 m² area in three parks of Panaji city, India. Standard methods were followed to derive carbon stock and sequestration rates by trees, hedge plants, and groundcover. Notwithstanding wide differences between tree species, the weighted mean of CO₂ sequestered per tree averaged 55 kg y⁻¹ (ca. 78.82 tons ha⁻¹) in Panaji city. Accordingly, the CO₂ sequestration potential of trees, in the UGS of Panaji (by 76,751 trees) and Tumkur (with an estimated 38,152 trees) cities, respectively, was 4221.31 tons y⁻¹ ha⁻¹ and 2098 tons ha⁻¹ y⁻¹ @ 55 kg tree⁻¹ y⁻¹. It is apparent from this first-time study that calculated tree carbon biomass and species-wise yearly carbon sequestration rates (CSRs) of 78.82 tons ha⁻¹ y⁻¹ and that of carbon production rates of 31.77 tons ha⁻¹ y⁻¹ are far higher than the previously reported CSR estimates variously from 1 to 8 tons ha⁻¹ y⁻¹ and carbon production rates 3.23 to 6.55 tons ha⁻¹ y⁻¹. The hedge row carbon biomass averaged 13.18 tons ha⁻¹ and sequestration of 48.38 tons ha⁻¹ y⁻¹ CO₂. Similarly, occupying over 42% of the UGS, the groundcover carbon biomass averaged 14.69 tons ha⁻¹ with sequestration of 53.92 tons CO₂ ha⁻¹ y⁻¹. Combined CSP of existing trees, groundcover, and hedge plants in Panaji and Tumkur city UGS apparently neutralize carbon footprint of over 4550 and 2200 Indians at an annual per capita emission of 1.94-ton. It is thus undeniable that in our global fight against climate change, the addition of inputs and data from studies like these can aid in planning mitigation measure as well as in fulfilling local/regional sustainability plans and needs. Full article

Increasingly stringent regulations regarding climate policy and the sustainable development paradigm determine the transformation of contemporary multi-family housing typology, manifested by a growing share of single-aspect micro-apartments (units with exterior exposure on only one facade). This article identifies the phenomenon of the energy-efficiency paradox, wherein highly insulated buildings successfully trap winter heat but inadvertently escalate summer cooling demands. Consequently, the primary operational challenge becomes limiting excessive solar heat gains in summer, which directly translates into high cooling energy demand, rather than solely mitigating heat losses in winter. Sustainable construction requires moving beyond the narrowly defined reduction of envelope thermal transmittance towards holistic adaptation to climate change and ensuring adequate indoor environmental quality. The methodology is based on a coupled energy-economic analysis, evaluating thermal balances and their direct financial implications for end-users. The variant analysis of solar heat gains conducted for a reference 30 m² dwelling in Warsaw proves that architectural optimization should not be determined solely by short-term investment profit maximization. Effective engineering optimization in construction requires the implementation of a full building life cycle perspective. Unfavorable glazing orientation and the lack of cross-ventilation necessitate the use of energy-intensive air-conditioning systems, which directly increases the building’s carbon footprint and generates hidden operating costs (differences reaching over 145 PLN annually for heating and approximately 70 PLN for cooling). The findings highlight the necessity for a critical reevaluation of design priorities for compact apartments, integrating social justice (by reducing information asymmetry in the real estate market, where buyers are often unaware of these future cooling burdens) with long-term economic rationality and the resilience of the built environment to extreme weather events. Full article

Life cycle assessment (LCA) studies of polypropylene (PP) processing commonly rely on generic secondary databases, while primary industrial inventories for plastic conversion processes remain scarce. This study addresses this gap by quantifying the cradle-to-gate carbon footprint of polypropylene processing using anonymised primary industrial data collected in 2024 from four European polypropylene processing facilities. Unlike previous studies relying mainly on generic secondary inventories, the proposed approach combines primary industrial data with sensitivity and scenario analyses to identify practical priorities for emission reduction. The baseline carbon footprint was estimated at 1.44 tCO₂e per tonne of finished product, with material production and energy-intensive processing identified as the major emission hotspots. One-Factor-at-a-Time (OFAT) sensitivity analysis showed that polypropylene type, process efficiency, renewable electricity use, and process waste management were the most influential parameters, whereas water consumption and additive use had only a minor effect on overall emissions. Scenario analysis indicated that combining recycled polypropylene, improved process efficiency and renewable electricity reduced emissions by 45.8%, while reducing process waste and fully recycling production residues achieved a 42.2% reduction compared with the baseline. By integrating primary industrial inventory data with sensitivity and scenario analyses, this study provides a more representative assessment of real industrial polypropylene processing conditions than approaches based solely on generic databases and identifies practical priorities for industrial carbon mitigation. Full article

Alkali-activated materials (AAMs) are widely regarded as promising alternatives to ordinary Portland cement for marine engineering because of their low carbon footprint, efficient utilization of industrial by-products, and potentially favorable mechanical and durability performance. However, their long-term application in marine environments remains challenging, as the original advantages of AAMs can be progressively weakened by the individual and coupled actions of aggressive seawater ions, particularly chloride (Cl⁻), sulfate (SO₄²⁻), and magnesium (Mg²⁺). These ions affect AAMs through distinct but interconnected mechanisms, including chloride binding and transport, competitive ion interactions, phase transformation, destabilization of reaction products, pore-structure evolution, and the subsequent degradation of macroscopic properties. Meanwhile, the response of AAMs to marine exposure is highly system-dependent, since precursor chemistry, activator design, reaction-product assemblage, and pore structure strongly govern their resistance to ion attack. In recent years, considerable efforts have been devoted to improving the marine durability of AAMs through composition and phase design, pore-structure refinement, and transport control. Nevertheless, current understanding remains fragmented, particularly regarding the coupled effects of multiple seawater ions and the links between microstructural evolution and long-term performance. The primary purpose of this review is to provide a systematic overview of the marine durability of AAMs from the perspectives of multi-ion threats, material-dependent responses, and existing mitigation strategies. Particular emphasis is placed on the roles of Cl⁻, SO₄²⁻, and Mg²⁺, the controlling effects of precursor and activator chemistry, and the translation of micro-mechanisms into macroscopic durability evolution. By integrating these aspects within a unified framework, this review aims to support the design and application of AAMs for reliable long-term use in coastal and offshore engineering. Future research should prioritize standardized multi-ion exposure protocols, coupled transport–reaction models, long-term field validation, and durability assessment of reinforced AAM concretes under realistic marine conditions. Full article

Microalgal lipid extraction, particularly the subsequent solvent recovery phase, constitutes the primary energy bottleneck in algal-based biodiesel biorefineries. Recently, switchable polarity solvents (SPS), such as the tertiary amine N,N-dimethylcyclohexylamine (DMCHA), have emerged as promising ‘green’ alternatives capable of extracting lipids directly from wet biomass, theoretically bypassing energy-intensive drying and solvent recovery distillation stages. This study presents a rigorous techno-energetic and thermodynamic evaluation combined with supporting experiments for qualitative conclusions to scrutinize the actual viability of DMCHA-mediated extraction against conventional hexane benchmarks, across three process configurations using different biomass types: algal liquor, wet paste, and dried biomass. Contrary to widespread assumptions in the literature, fundamental thermodynamic calculations reveal that the energy required for amine regeneration via protonation/deprotonation mechanisms equals or exceeds that of conventional distillation. Furthermore, mitigating biomass drying inadvertently escalates overall downstream energy and economic penalties due to the excessive solvent volumes demanded by dilute aqueous matrices. Direct extraction from algal liquor displays a cost and energy consumption countably higher than the other scenario; precisely, a cost of 232 €/kg of lipids and energy consumption of 454 kWh/kg of lipids. Extraction from wet paste exhibits, indeed, a slightly lower energy consumption compared to the hexane process (respectively 51 kWh/h versus 72 kWh/kg), but, due to the CO₂ requirements, the cost is double (19 €/kg of lipids versus 8 €/kg of lipids). Ultimately, while switchable polarity chemistry offers a marginal reduction in process water footprints, it introduces substantial operational complexity, elevated carbon dioxide payloads, and severe solvent degradation risks, challenging its current readiness for industrial upscaling. Full article

This study evaluates the economic and carbon footprint impact of using calcium lignosulfonate (CLS) in stabilizing highway subgrade on road pavement. Specifically, the effect of stabilized soil strength on layer thickness, costs, and carbon emissions during the initial construction phase was investigated. Two different soil types (clayey and sandy) were used with varying CLS concentrations. Furthermore, the performance of CLS was evaluated using sodium hydroxide-based alkaline activation (AAS). Standard proctor, unconfined compressive strength (UCS), and California bearing ratio tests were applied to the prepared samples. The experimental results showed that CLS significantly increased the CBR and UCS values of the soil samples. Additionally, it was calculated that the initial construction costs of flexible and rigid road pavements designed on stabilized clayey soil decreased by 14.34% and 25.24%, respectively, while on sandy soils, the decreases were 8.10% and 14.95%, respectively. Meanwhile, it has been determined that CO₂ emissions were reduced by up to 10.76% in flexible pavement designs and by up to 17.88% in rigid pavement designs. Consequently, these findings show that the use of CLS in soil stabilization enables both a reduction in the layer thickness of road pavement designs and a reduction in environmental impacts. Full article

To mitigate the environmental footprint of the aviation sector, this study proposes an integrated cascading biorefinery scheme to produce Sustainable Aviation Fuel (SAF) precursor bloodstock via enzymatic transesterification of coconut oil. Utilizing a synergistic binary alcohol system (ethanol-butanol) and the liquid lipase Eversa Transform 2.0, a strategic molecular reconfiguration of fatty acid esters was achieved. Optimization through Response Surface Methodology (RSM) identified critical parameters—5% catalyst loading, total binary alcohol-to-oil molar ratio of 7:1 (specifically comprised of a 2.5:4.5:1 ethanol/butanol/coconut oil matrix), and an operation temperature of 57.5 °C—yielding a 97% conversion efficiency. A sequential vacuum fractional distillation process was implemented to partition the ethyl-butyl esters into high-value streams. Notably, the light distillate fraction, characterized by a specific carbon chain distribution (C6: 27.2%, C8: 52.5%, C10: 6%, and C12: 13.6%), perfectly aligns with the molecular window of aviation kerosene. This fraction exhibits excellent cold-flow properties, viscosity, and volatility profiles, positioning it as an ideal high-performance SAF precursor blendstock to increase the renewable content of current aviation fuels. Simultaneously, the remaining C16–C18 residue serves as a high-density energy source for internal refinery processes, while C8–C14 species are recovered as high-purity chemical feedstocks. This circular model maximizes carbon atom economy and economic viability by cogenerating high added-value biochemicals alongside jet-grade blendstocks. These findings provide a scalable, enzymatic framework for the next generation of decarbonized aviation fuels. Full article