Search Results (1,612)

Developing low-carbon building materials is essential for achieving sustainability in the construction sector. This study proposes a carbon-negative concrete (CNC) system that combines low-carbon binders derived from industrial by-products with carbonated recycled aggregates capable of CO₂ absorption. To enhance particle packing and mechanical performance, the Modified Andreasen–Andersen (MAA) model was adopted for mix design optimization and experimentally validated. The optimized CNC mixture containing 22% coarse aggregate achieved the minimum residual sum of squares between the graded particle distribution and the theoretical MAA curve, as well as the highest strength performance. Compared with a 14% coarse aggregate mixture, the 22% mix exhibited 13.5% and 19.8% increases in compressive strength at 7 and 28 days, confirming the applicability of the MAA model for CNC proportioning. Carbon emission assessment, limited to raw material production, demonstrated significant environmental benefits. CNC incorporating both low-carbon binders and carbonated recycled aggregates reduced total emissions and CO₂ intensity by 87.1% and 86.2%, respectively, compared with ordinary concrete of the same strength grade. Economic evaluation further showed that CNC reduced material cost by 48.1% relative to ordinary concrete. It should be emphasized that the reported CO₂ reduction and negative emission effects are limited to the defined raw material production boundary and do not represent a fully net-negative life cycle. Overall, these results confirm the technical, environmental, and economic feasibility of CNC as a sustainable alternative to traditional concrete. Full article

Although greenhouse gas emissions have significantly reduced, the European Union still faces a major challenge in meeting its 2050 net-zero goal set under the European Green Deal. Focusing on the impacts of population, economic output, and carbon intensity of economy, this study employs Index Decomposition Analysis to estimate the reductions in carbon intensity needed to reach this target. The findings show that the extent of the technical effort required for decarbonization is much influenced by economic expansion. Under a 3% annual Gross Domestic Product growth scenario, the EU’s carbon intensity of economy must decline by 11.8% per year, which is a particularly demanding rate given the already low baseline. The decomposition also quantifies the technological challenge: under high growth, up to 5867 MtCO₂ in reductions would be needed by 2050 (compared with 1990), with Carbon Capture and Storage (CCS) contributing only 10–15%. In contrast, in zero- or negative-growth scenarios, required reductions fall to 4923–4594 MtCO₂, with CCS accounting for up to 50–90%. These results show that decarbonization in EU industrial sectors requires systemic transformations and strategic CCS deployment. A balanced approach, limiting economic growth and increasing innovation, appears essential to achieve the climate neutrality target. Full article

This study examines the environmental implications of energy-intensive cryptocurrency mining activities within the broader sustainability debate surrounding blockchain technologies. Focusing specifically on Bitcoin’s proof-of-work–based mining process, the analysis investigates the long-run relationship between greenhouse gas emissions, network-specific technical variables, and climate policy uncertainty using advanced cointegration and asymmetric causality techniques. The findings reveal a stable long-run association between mining-related activity and emissions, alongside pronounced asymmetries whereby positive shocks amplify environmental pressures more strongly than negative shocks mitigate them. Importantly, these results pertain to the mining process itself rather than to blockchain technology as a whole. While blockchain infrastructures may support sustainable applications in areas such as green finance, transparency, and energy management, the evidence presented here highlights that energy-intensive mining remains a significant environmental concern. Accordingly, the study underscores the need for active regulatory frameworks—such as carbon pricing and the polluter-pays principle—to reconcile the environmental costs of crypto mining with the broader sustainability potential of blockchain-based innovations Full article

As the global climate discourse shifts from mitigation to achieving net-negative emissions, there is a critical need for replicable, real-world models of climate-positive development at a regional scale, particularly in the Global South. This study addresses this gap by conducting a detailed greenhouse gas (GHG) inventory of four diverse provinces in Thailand and analyzing the results through the newly proposed Climate-Positive Pathways Framework (CPPF). Our findings reveal that all four provinces function as significant net-negative GHG sinks. They achieve this status through three distinct archetypes: a Conservation-Dependent pathway, an Agricultural Frontier pathway, and a novel Agro-Sink pathway. Most significantly, in the Agro-Sink model, we find that in specific economic contexts, managed agricultural landscapes can surpass natural forests as the primary driver of regional carbon removal. This typology provides a new, landscape-scale paradigm for cleaner production, proposing these three archetypes as transferable, evidence-based models for regional policymakers. This underscores that effective climate action requires context-specific regional planning that strategically leverages both natural and agricultural capital. Full article

In recent years, interest in carbon dioxide (CO₂) hydrogenation technologies has intensified. Driven by the continuous rise in greenhouse gas emissions and the unprecedented negative impacts of global warming, these technologies offer a viable pathway toward sustainability and support the development of low-carbon industrial processes. In addition to methanol and methane, other possible hydrogenation products (i.e., hydrocarbons, formic acid, acetic acid, dimethyl ether, and dimethyl carbonate) are of industrial relevance due to their wide range of applications. Therefore, this review aims to provide a comprehensive overview of the various aspects associated with thermocatalytic CO₂ hydrogenation processes, from thermodynamic and kinetic studies to upscaled reactor modeling and process synthesis and optimization. The review proceeds to examine different integration strategies and optimization approaches for multi-product systems, with the objective of evaluating how distinct technologies may be combined in an integrated flowsheet. It then concludes by outlining future research opportunities in this field, particularly those related to developing comprehensive kinetic rate expressions and reactor modeling studies for routes with low technology readiness levels, the exploration of prospective reaction pathways, strategies to mitigate the dependence on green hydrogen (which, today, exhibits high costs), and the consideration of market price or product demand fluctuations in optimization studies. Overall, this review provides a solid base to support other decarbonization studies focused on hydrogenation technologies. Full article

Carbon capture, utilization, and storage (CCUS) play an increasingly important role in climate mitigation strategies by addressing industrial emissions and enabling pathways toward net-negative emissions. A key challenge lies in determining the pathway of captured CO₂, whether through permanent geological storage or conversion into value-added products to enhance system viability. As hard-to-abate sectors and the power industry remain major sources of emissions, a comprehensive assessment of the technical, environmental, and economic performance of CCUS pathways is essential. This study evaluates bioenergy with carbon capture and storage/utilization (BECCUS) in the context of the Polish energy sector. Techno-environmental performance was assessed across three pathways: CO₂ storage in saline formations, CO₂ mineralization, and methanol synthesis. The results show levelized costs of 59.9 EUR/tCO_2,in for storage, 109.7 EUR/tCO_2,in for mineralization, and 631.1 EUR/tCO_2,in for methanol production. Corresponding carbon footprints (including full chain emissions) were −936.4 kgCO_2-eq/tCO_2,in for storage, −460.6 kgCO_2-eq/tCO_2,in in for mineralization, and 3963.4 kgCO_2-eq/tCO_2,in for methanol synthesis. These values highlight the trade-offs between economic viability and climate performance across utilization and storage options. The analysis underscores the potential of BECCS to deliver net-negative emissions and supports strategic planning for CCUS deployment in Poland. Full article

Electric vehicles (EVs) are widely promoted as a key strategy for reducing carbon dioxide (CO₂) emissions and advancing sustainable development. However, the real-world benefits of EV adoption may vary across countries with different income levels and energy systems. This study investigates the relationship between EV adoption and CO₂ emissions per capita, as well as overall sustainable development performance (SDG Index), across 50 countries from 2010 to 2023. Using panel quantile regression, we find that EV adoption is significantly associated with reduced CO₂ emissions particularly in the high-emitting countries in high-income countries (interaction coefficient at the 90th quantile = −0.24, p < 0.05) but positively associated with emissions in lower- and middle-income countries at lower quantiles of the emissions distribution. Similarly, while EV adoption correlates positively with the SDG Index in high-income countries, it shows negative effects at the median and several quantiles. These findings challenge the “zero-emission” assumption and demonstrate that the climate and development benefits of EV diffusion are context-dependent and unevenly distributed, highlighting the need for policies that link electrification to renewable energy deployment, infrastructure development, and equitable access. Full article

This research focuses on Henan, a key agricultural region, analyzing data from 2000 to 2022 on cropland use and agricultural input–output. It employs the Tapio decoupling model to examine the evolution and decoupling of cropland use intensity (CLUI) and cropland use carbon emissions (CUCE) in the province. The study reveals that from 2000 to 2022, CLUI in Henan Province fluctuated in a “high-low-high” pattern over time, creating a spatial distribution with high-intensity areas in the east and lower-intensity areas at the provincial boundaries. CUCE showed a “U” shaped trend, peaking around 2015 and then gradually declining. Spatially, emissions were consistently higher in the south and lower in the north. The relationship between CLUI and CUCE transitioned from a strong negative decoupling from 2000 to 2010, to a strong decoupling from 2015 to 2020, and to a recessive decoupling from 2020 to 2022. Spatially, it evolves from a state of negative decoupling across the entire region in the early stage to nearly full coverage of strong decoupling regions in the later stage. Based on these insights, the study suggests planning strategies focusing on regional management and policy alignment, providing scientific guidance for sustainable cropland use and optimized territorial planning in Henan Province. Full article

Swine manure, a heterogeneous livestock waste composed of solid and liquid excreta, can be sustainably converted through Chemical Looping Gasification (CLG) to produce syngas and bioenergy. Integrated with CO₂ capture, the process enables high-purity hydrogen generation and offers a potential route toward net-negative carbon emissions. The experimental campaign was conducted at 900 °C in a continuously operated 0.5 kW_th CLG unit consisting of two interconnected fluidized bed reactors (fuel and air). Ilmenite was employed as the oxygen carrier to provide the oxygen required for gasification. This study focuses on the gasification of raw swine manure, comprising both solid and liquid fractions. The solid fraction was introduced via a screw feeder, while the liquid fraction was simulated by injecting an ammonia–water solution as gasifying agents (water or ammonia + water). The effect of the liquid fraction on syngas composition, carbon conversion, and nitrogen species (N₂, NH₃, N₂O, NO₂, and NO) was evaluated at ammonia concentrations typical of swine manure (800–5600 mg/L). Results showed an average syngas composition for solid and liquid fraction feeding of ~31% CO₂, 20% CO, 41% H₂, 7% CH₄, and 0.5% C₂ hydrocarbons, with 91–96% carbon conversion. Benzene and naphthalene dominated the tar compounds. CO₂ capture potential reached 60%, with nitrogen mainly converted to N₂. Full article

Against the backdrop of global climate governance and China’s “dual carbon” goals, carbon emissions trading (CET) has become a core policy instrument for promoting low-carbon transformation. However, it remains unclear whether CET policies can effectively improve corporate carbon performance and, more importantly, through which micro-level mechanisms such effects operate within firms. To address these gaps, this study applies a difference-in-differences (DID) approach to examine the impact of CET policy on corporate carbon performance and its transmission pathways. The results show that CET policy significantly enhances corporate carbon performance. Heterogeneity analysis further reveals that this positive effect is more pronounced in regions with lower environmental governance intensity, and that the policy’s effectiveness strengthens over time. Mechanism tests indicate that financing constraints and R&D investment serve as chain mediators: CET policy alleviates financing constraints, stimulates R&D investment, and thereby improves carbon performance. Moreover, the moderating effect analysis shows that executives’ green backgrounds reinforce the policy’s effectiveness by further easing financing constraints and mitigating their negative impact on R&D investment. Overall, these findings deepen the micro-level understanding of market-based environmental regulation and provide policy implications for optimizing CET policy design, improving resource allocation efficiency, and fostering low-carbon transformation and sustainable competitive advantages for enterprises. Full article

Using panel data from 273 prefecture-level cities in China from 2008 to 2020, this study employs the Entropy Weight Method -Technique for Order Performance by Similarity to Ideal Solution (EWM-TOPSIS) model to measure people’s well-being and applies a staggered Difference-in-Differences (DID) model to evaluate the impact of the carbon emissions trading system on people’s well-being. The findings indicate that the carbon emissions trading system generally improves people’s well-being. The mechanism analysis reveals that the primary channel through which the carbon emissions trading system improves people’s well-being is the stimulation of green technology innovation. Additionally, fiscal expenditure decentralization negatively moderates the carbon emissions trading system’s impact on people’s well-being, whereas marketization degree does not exert a moderating effect. Further research reveals that fiscal expenditure decentralization exhibits a double threshold effect, while the degree of marketization displays a single threshold effect. The carbon emissions trading system exhibits heterogeneous impacts on people’s well-being. From a regional perspective, the carbon emissions trading system enhances people’s well-being in non-Yangtze River Economic Belt (YREB) regions, whereas it dampens people’s well-being in YREB cities. Regarding resource endowment, the carbon emissions trading system positively influences people’s well-being in non-resource-based cities, but its impact remains statistically insignificant in resource-based cities. Full article

Environmental health concerns remain a major global challenge. In many nations, the adoption of measures to mitigate the negative environmental impacts of construction-related activities has been slow. Prior research has clarified that further study/advancement are required to improve environmental health/sustainability (EHS). To determine the focus of previous studies, this study attempts to identify, analyse, and visualise the trends in research concerning EHS in construction-related domains. The data were obtained from the Scopus database, and the study employed a bibliometric approach. The following keywords were used to search the database: ‘environmental health’ OR ‘ecological health’ OR ‘environmental sustainability’ OR ‘ecological sustainability’ OR ‘Environmental safety’ OR ‘ecological safety’ AND ‘construction industry’ OR ‘building industry’ to retrieve relevant documents. The analysis included co-citation analysis, keyword co-occurrence and trend mapping. The findings revealed four themes: Environmental Sustainability and Energy-Oriented Decision-Making, Low-Carbon Cementitious Materials and Mechanical Performance of Concrete, Waste Management and Circular Economy Practices, and Life Cycle Assessment and Carbon Emission Analysis. The keyword findings revealed very scant research in environmental health unlike environmental sustainability. Spain, China, and Saudi Arabia are the top three in terms of citation-to-publication ratio, indicating strong influence in literature sources. However, India has the highest number of publications. The findings also suggest that more relevant studies are required in African nations and South Asian countries. It further highlighted a knowledge gap that emerging economies must address to enhance the sustainability and environmental performance of construction projects. This bibliometric analysis is unique in its integrated examination of environmental sustainability and environmental health in the construction industry, employing strategic thematic mapping to reveal system-level linkages, contextual gaps, and targeted directions for future research. The conclusions provide scholars and stakeholders in the built environment with a solid theoretical basis, enhancing the industry’s preparedness to mitigate the adverse environmental and climatic impacts of traditional construction methods. Full article

The behavior of the carbon cycle within the Land-Ocean Aquatic Continuum (LOAC) is shaped not only by aquatic processes but also by chemical interactions occurring at the atmosphere–water interface. In particular, the transport of acid rain precursors such as SO₂ and NO_x to surface waters via deposition can alter the water’s pH balance, thereby affecting Dissolved Inorganic Carbon (DIC) fractions and CO₂ emission potential. In this study, air quality measurements from three monitoring stations (Bosna, Karatay, and Meram) in Konya province of Türkiye, along with precipitation and temperature data from a representative meteorological station for the period 2021–2023, were analyzed using the Mann–Kendall Trend Test. Additionally, seasonal pH values of groundwater were examined, and their trends were compared with those of the other variables. The findings reveal striking differences on a station basis. At the Bosna station, while NO (Z = 10.80), NO₂ (Z = 9.47), and NO_x (Z = 10.04) showed strong increasing trends, O₃ decreased significantly (Z = −15.14). At the Karatay station, significant increasing trends were detected for CO (Z = 10.01), PM₁₀ (Z = 8.59), SO₂ (Z = 5.55), and NO_x (Z = 2.44), whereas O₃ exhibited a negative trend (Z = −6.54). At the Meram station, a significant decrease was observed in CO (Z = −11.63), while NO₂ showed an increasing trend (Z = 3.03). Analysis of meteorological series indicated no significant trend in precipitation (Z = −0.04), but a distinct increase in temperature (Z = 2.90, p < 0.01). These findings suggest that the increasing NO_x load in the Konya atmosphere accelerates O₃ consumption and, combined with rising temperatures, creates a potential for change in the carbon chemistry of aquatic systems. The results demonstrate that atmospheric pollutant trends constitute an indirect but significant pressure factor on the aquatic carbon cycle in semi-arid regions and highlight the necessity of integrating atmospheric processes into carbon budget analyses within the scope of LOAC. Full article

Global warming has become a top priority on the international environmental policy agenda. The recent rise in CO₂ emissions observed in Türkiye has further emphasized the country’s critical role in addressing climate change. This study aims to estimate Türkiye’s CO₂ emissions through 2030 and identify the key socioeconomic and environmental factors driving these emissions, using multiple linear regression (MLR) and time series analysis methods. Six primary variables are examined: population, gross domestic product (GDP), CO₂ intensity, per capita energy consumption, total greenhouse gas (GHG) emissions, and forest area. This study introduces a new multivariate forecasting framework that integrates time series projections with multiple linear regression and elasticity-based sensitivity analysis, providing novel insight into the relative influence of key emission drivers compared to prior research. The results suggest that, if current policy trends persist, Türkiye’s CO₂ emissions will increase substantially by 2030. Variables such as GHG emissions, energy consumption, and population growth are found to have an increasing effect on emissions, while the limited expansion of forest areas is insufficient to offset this trend. In contrast, the negative correlation between GDP and CO₂ emissions suggests that economic growth can occur in alignment with environmental sustainability. The model’s validity is supported by a high R² (0.99) value and low error rates. The findings indicate that Türkiye must reassess its current strategies and strengthen policies targeting renewable energy, energy efficiency, and carbon sinks to achieve its climate goals. The proposed framework provides a transparent basis for climate planning and policy prioritization in Türkiye. Full article

Biomass gasification, as a thermochemical process, has attracted growing interest due to the increasing popularity of biofuel production based on syngas or pure hydrogen. Moreover, when integrated with CO₂ capture, this method of producing gaseous fuels can achieve negative CO₂ emissions, making it competitive with other production systems based on either fossil or renewable sources. This paper presents the results of a process and economic analysis of synthetic natural gas (SNG) production systems integrated with a commercial fluidized-bed gasification reactor based on Synthesis Energy Systems (SES) technology. The study examines the potential integration of the system with a water electrolyzer at two levels of coupling: one providing oxygen for the gasification process, and the other eliminating the need for CO₂ separation before the SNG synthesis stage. Using a single gasification unit with a raw biomass feed rate of 60 t/h, the system produces 188 t/d of SNG. Integration with a water electrolyzer increases SNG production to 259 and 621 t/d. For cases without electrolyzer integration and under the assumption of zero emissions from biomass processing, the application of CO₂ separation enables the achievement of negative CO₂ emissions. This creates an opportunity for additional revenue from the sale of CO₂ emission allowances, which can significantly reduce SNG production costs. In this analysis, the break-even CO₂ price, above which the SNG production cost becomes negative, is USD 251/t CO₂. In systems integrated with water electrolysis, the cost and carbon footprint of the electricity consumed in the electrochemical water-splitting process have a decisive impact on both the overall SNG production cost and its carbon intensity. Full article