Search Results (40)

Urban carbon neutrality is increasingly shaped by cross-regional interactions rather than a closed balance between local emissions and sequestration. From an open-system perspective, this study conceptualizes urban carbon neutrality as the outcome of interactions between embodied carbon transfer (ECT) and carbon sequestration service flows (CSSFs). Using panel data for 297 Chinese cities in 2012, 2017, and 2022, an integrated measurement framework is developed to examine spatiotemporal patterns, typological heterogeneity, and driving mechanisms. The results reveal significant disparities in emission responsibility and ecological support across city types. Ecological conservation-oriented cities act as major carbon sequestration providers, while industrial- and service-oriented cities face higher emission pressures and weaker local sequestration capacity. The joint effects of ECT and CSSF reshape urban carbon neutrality through responsibility reallocation and ecological support transfer, enhancing overall performance while intensifying inter-city differentiation. Spatial Durbin model results indicate that carbon neutrality is jointly influenced by socioeconomic development, energy structure, factor mobility, ecological conditions, and institutional regulation, with both local and spillover effects. These findings suggest that urban carbon neutrality is a relational process embedded in production–consumption linkages and ecosystem service networks, highlighting the need for differentiated governance pathways to support coordinated mitigation and ecological compensation. Full article

This study examines how regulatory heterogeneity in digital services trade relates to the carbon intensity of bilateral trade flows. Using a structural gravity framework estimated with Poisson pseudo maximum likelihood (PPML), we analyzed 10,719 bilateral observations from the Eora Multi-Region Input–Output (MRIO) database over 2014–2020. Bilateral gaps in the OECD Digital Services Trade Restrictiveness Index (DSTRI) were used as the main measure of regulatory heterogeneity, and the overall gap was decomposed into infrastructure-related hard barriers and institutional soft barriers. The results suggest that digital regulatory gaps are associated with a higher carbon intensity in trade while also being associated with lower total embodied emissions through reduced trade volumes. This indicates that lower aggregate emissions under regulatory divergence may reflect contraction in trade activity rather than genuine environmental improvement. The decomposition analysis further suggests that infrastructure-related misalignment is more closely associated with carbon inefficiency, whereas institutional divergence operates mainly through its association with trade volume. In addition, environmental policy stringency in the importing country appears to strengthen the positive association between institutional regulatory gaps and carbon intensity, consistent with the possibility of regulatory overload. The study contributes to the sustainability literature by showing that carbon intensity provides a more informative indicator of sustainable trade performance than aggregate emissions alone in fragmented regulatory environments. It also suggests that digital governance, trade policy, and environmental policy should be considered together in promoting more sustainable forms of international trade, particularly in the context of emerging policy frameworks such as WTO digital trade negotiations, OECD digital governance initiatives, and carbon border adjustment mechanisms (CBAMs). Full article

China’s rapid electric vehicle (EV) market expansion—from 331,000 units in 2015 to over 9.5 million in 2023—is generating an unprecedented wave of retired lithium-ion batteries projected to exceed 94 TWh cumulatively by 2060, presenting critical challenges for sustainable resource management. While grid decarbonization can reduce use-phase emissions, the substantial embodied carbon in battery production (55–130 kg CO₂-eq/kWh) remains a critical challenge for achieving carbon neutrality. This study presents an integrated dynamic material flow analysis (MFA) and prospective life cycle assessment (LCA) framework—calibrated against the latest peer-reviewed literature—to quantify the carbon mitigation potential of battery recycling and second-life applications from 2020 to 2060. We evaluate four end-of-life management scenarios: baseline linear economy, enhanced recycling, second-life dominant, and synergistic optimization. Our results reveal that the synergistic scenario achieves the highest cumulative avoided emissions of 3844 Mt CO₂-eq, representing a 12.1-fold improvement over the baseline. Monte Carlo uncertainty analysis (n = 10,000) confirms robust scenario differentiation, with 100% probability that synergistic optimization outperforms enhanced recycling alone. Material security analysis shows that recycled supply can meet 100% of lithium, cobalt, nickel, and copper demand by 2060 under optimal management. These findings provide quantitative evidence for chemistry-differentiated battery management policies aligned with China’s dual carbon goals and the transition toward a sustainable circular economy. Full article

The year 2020 marked the eve of the explosive growth in China’s BEV market, which may lead to substantial carbon emission implications. This study quantifies the full life-cycle carbon emissions of battery electric vehicles (BEVs) across China’s 31 provinces using a multi-regional input-output-based life-cycle assessment (MRIO-based LCA) model, covering four phases: manufacturing, driving, battery replacement, and scrapping. Moreover, the coupling coordination degree (CCD) model was employed to evaluate the coordination degree between provincial BEV deployment and a green electric system. Results show that the total carbon emissions amount to 48.95 million tons, with manufacturing contributing 58.4% and driving for 33.4%. Hebei (5.72 million tons) and Shandong (4.16 million tons) account for the largest shares, driven by embodied emissions from heavy industry and coal-intensive power systems. Interprovincial embodied carbon flows reveal a dominant north-to-south transfer pattern. Furthermore, coupling coordination between BEV deployment and a green electric system is generally medium (0.5 < CCD ≤ 0.7), with Guangdong (CCD = 0.73) standing out as an exemplary case, demonstrating an effective equilibrium between BEV industry expansion and the integration of renewable energy. These findings highlight that in provinces with rapidly growing BEV industries, such as Guangdong, policies promoting low-carbon supply chains and accelerating green electricity infrastructure development are crucial to reducing emissions. Full article

Circular economy (CE) decouples value creation from virgin resource use and waste in the medical device sector, which faces stringent patient-safety, quality, and regulatory obligations. Green Additive Manufacturing (AM) offers a precise, digitally driven route to implement CE through dematerialization, on-demand localized production, topology optimization, and material circularity. In this study, a comprehensive CE framework is tailored to medical device manufacturing that integrates eco-design, material circularity, remanufacturing, and regulatory compliance across the product life cycle. Methods include an International Organization for Standardization (ISO) 14040/44-aligned life cycle assessment, process energy metering, sterilization-compatibility studies, mechanical/biocompatibility verification to relevant standards, and a techno-economic/circularity analysis with Monte Carlo uncertainty quantification. Three case studies are explored using bio-based PA11 (selective laser sintering), recycled polyethylene terephthalate glycol (fused deposition modeling), and low-volatile organic carbon biocompatible photopolymer (stereolithography): (1) a patient-specific wrist orthosis, (2) a dental surgical guide, and (3) a single-use catheter Y-connector. Results indicate 38–68% reductions in embodied greenhouse-gas emissions, 22–54% energy savings per functional unit, and up to 80% mass recapture through in-process powder/runner reuse while maintaining clinical performance and regulatory conformity. Design-for-circularity patterns (DfC) were created for DfDisassembly, DfSter, DfTraceability, DfUpgrade, and DfPowder-Loop and provide a governance architecture combining ISO 13485 QMS, ISO 10993 biological evaluation, the European Union’s Medical Device Regulation (Regulation (EU) 2017/745), and the United States Food and Drug Administration’s guidance on Additive Manufactured (3D-printed) medical devices, guidance with unique device identification for closed-loop returns. The paper concludes with an Industry 5.0 roadmap for hospital-proximate micro-factories, materials passports, and digital product passports enabling verified circular flows at scale. Full article

The accelerating climate emergency places the built environment under increasing pressure as both a major source of greenhouse gas emissions and a system highly vulnerable to climate impacts. Buildings contribute substantially to global operational energy use and embodied carbon, while much of the existing stock remains poorly adapted to changing climatic conditions. This paper examines the role of artificial intelligence (AI) in improving energy efficiency, enabling circular material flows, and enhancing resilience across the building lifecycle. Based on a structured synthesis of recent peer-reviewed literature, institutional reports, and documented case examples, the study maps AI applications in design, construction, operation, and end-of-life stages, including generative design, predictive maintenance, digital twins, and construction and demolition waste analytics. The analysis shows how AI can reduce operational energy demand, optimize material use, and support reuse and recycling strategies, while enabling new software-driven business models in the building sector. The paper argues that AI’s effectiveness depends on data availability, interoperability, regulatory alignment, and workforce capabilities, and that its benefits are maximized when integrated with circular economy strategies and supportive policy and financial frameworks. This integrated perspective highlights pathways for reducing emissions and improving the resilience of the built environment under climate stress. Full article

In low-carbon transition policy management, rationally determining the energy-related carbon emission responsibilities (ERCERs) across multiple regions is a fundamental issue. Reasonable allocation must take into account regional heterogeneities, such as energy endowments, economic development levels, industrial structures, and complex interconnections within the multi-regional energy supply chain. Previous studies mostly analyzed it via the multi-regional input–output (MRIO) model on the energy-consumption side, often neglecting the regional distribution of energy production and inter-regional energy transport on the energy-production side. This limitation risks a mismatch between energy policies and economic policies in practical policy governance. To address this gap, this study develops an energy allocation-induced MRIO (EA-MRIO) method integrating energy allocation analysis and an MRIO model to trace ERCER transmissions holistically across the entire energy supply chain. The framework covers seven stages including energy supply, inter-regional energy transport, direct energy consumption of end-use sectors, inter-regional intermediate products input and output, final products supply, inter-regional final products transport, and final demand, applied to a case study of China’s 31 provinces in 2017. Results show that ERCERs mainly transfer from western and northern regions to eastern and southern coastal areas: ERCERs embodied by energy production in western and northern provinces first flow to northern coastal provinces (main intermediate products producers), then to eastern and southern coastal provinces (main final products producers), with 23% ultimately attributed to exports. These findings call for allocating ERCERs based on different subregions’ roles within the national energy–economic system to facilitate more equitable and effective carbon reduction policymaking. Full article

From an ecological protection perspective, clarifying the spatial and temporal transfer characteristics of embodied carbon in water transport trade among BRICS countries and its driving mechanisms is of great significance for the precise formulation of emission reduction policies. This study integrates the multi-regional input–output model with the LMDI decomposition method to quantitatively analyze the bi-directional flow of embodied carbon in water transport trade among BRICS countries from 1995 to 2018, along with its spatio-temporal differentiation patterns. The driving mechanisms are decomposed across three dimensions: scale, structure, and intensity. By adopting a dual perspective of time-series and spatial correlation, the study systematically uncovers the cross-regional transfer patterns of embodied carbon emissions in water transport trade and examines the interaction pathways of various effects throughout their dynamic evolution. The study finds that (1) the embodied carbon in water transport trade among BRICS countries shows a trend of transnational transfer, with China being the largest net exporter (35.15 Mt in 2018), India and South Africa as net importers (−32.00 Mt and −1.89 Mt in 2018, respectively), and Brazil and Russia shifting from net importers to net exporters; (2) from a temporal perspective, the scale effect drives the growth of embodied carbon emissions (contribution values: 1.23~119.72 Mt for export trade; 4.88~34.36 Mt for import trade), while the intensity effect has a suppressive role (contribution values: −59.08~−1.48 Mt for export trade; −20.56~−5.31 Mt for import trade), and the structural effect is complex in its impact on emissions (contribution values: −17.72~0.45 Mt for export trade; −6.84~13.93 Mt for import trade). Optimizing the trade structure can help reduce carbon emissions; (3) from a spatial perspective, carbon emissions are higher in Southeast Asia and the Northern Hemisphere, and changes in China’s carbon emissions (total effect in 2018: 57.01 Mt in export trade and 7.98 Mt in import trade) significantly affect other BRICS countries. Based on the conclusions of the study, it is suggested that BRICS countries should strengthen cooperation to achieve regional emission reduction targets by optimizing the trade structure of water transport, promoting energy structure reforms, advancing green transport technologies and equipment, and establishing a carbon emission regulatory system. Full article

Land use supports production and living activities and provides ecosystem services for people. With the flow of capital, goods, and services among regions, trade leads to the transfer of carbon emissions from importing regions to exporting regions, and this is telecoupled with land systems in different regions. Although significant progress has been made in quantifying embodied carbon emissions induced by interprovincial and international trade, the telecoupling relationship between carbon emissions and land systems has not been sufficiently investigated. Here we followed the telecoupling theoretical framework and used the multi-region input–output (MRIO) model to examine the spatial pattern of embodied carbon emissions by land use in China due to interprovincial trade. The results show that the spatial patterns of embodied carbon emissions from the production end and from the consumption end are different based on land use type. The provinces with rich energy resources and favorable conditions such as Inner Mongolia, Xinjiang, and Heilongjiang undertake carbon emissions from the agricultural and industrial land use of other provinces. In contrast, the provinces with large economies but scarce resources such as Zhejiang and Guangdong export larger portions of their carbon emissions to the land use of other provinces. Across China, developed regions generally exported more carbon emissions from land use than they undertake from other developing regions. The carbon transfer in agricultural land was prominent between the eastern and western regions. The carbon emissions of industrial land were generally transferred from southern regions to northern and western areas. Our research reveals different patterns of embodied carbon emissions for different land use types, and these findings could provide more detailed information for policy-making processes to achieve fair carbon emissions and sustainable land use. Full article

Global construction activity remains the least responsive large economic sector to the exigencies of global climate change. The focus has centered on operating emissions of buildings, while upfront embodied emissions in building materials remain unabated. Softwood timber, a commonly used building material, can remove and store atmospheric carbon in buildings for decades. However, the upfront climate benefits of using softwoods in building frames are limited due to the multi-decadal growth and harvest cycles of forest plantations. The objective of this study was to demonstrate that fast-growing Eucalyptus is a superior carbon sequestration feedstock for building materials compared to slow-growing softwoods. We quantified the relative carbon benefits of Eucalyptus to a group of commonly used North American softwoods in an all-carbon-pools, risk-adjusted model that compares the net present value of carbon flows over a 100-year period. Using a novel carbon benefit multiple metric, the analysis shows that short-rotation, high-yield Eucalyptus plantations are 2.7× to 4.6× better at sequestering atmospheric carbon than softwoods, depending on the various risk perception scenarios. The results indicate that building decarbonization can be enhanced by using fast-growing and high-yielding Eucalyptus species plantations. Full article

The rapid increase in global agricultural trade has drawn increasing attention to greenhouse gas (GHG) emissions stemming from agricultural activities. Through the application of multi-regional input–output modeling and complex network analysis, this study links embodied GHG emissions with the agricultural trade network especially focusing on Asia and the Pacific countries. The results showed a consistent upward trend in the total amount of direct agricultural GHG emissions associated with both production and consumption activities. However, the embodied agricultural GHG emissions exhibited a larger scale and higher growth rate. Among them, the pathways from Brazil to China and the United States to China are the largest net emission flows within this area. Regional clusters were observed in North America, Western Europe, and Southeast Asia, and their agricultural GHG patterns showed evolutionary characteristics. By depicting embodied agricultural GHG emissions and identifying GHG emission transfer patterns, this study aimed to promote agricultural GHG emission reduction strategies, which attempt to promote sustainable development by encouraging the low-carbon agricultural industry. Full article

Embodied carbon flows among regions have led to unfair carbon emission responsibility accounting based on production. However, the heterogeneity of carbon peaking stress between regions is significantly neglected for those embodied carbon flows. Incorporating the carbon peaking stress into the embodied carbon flows can more clearly show what causes the carbon peaking stress and which carbon flow paths are more critical. In this study, the decoupling index of carbon emissions and economy development was applied to characterize the carbon peaking stress in each region, and the environmental extended multi-regional input–output model was applied to re-evaluate the criticality of regional embodied carbon flows. The results showed that the carbon peaking stress in China improved from 2007 to 2012, but the rebound of carbon peaking stress in 2017 made most regions reverse the previous downward trend. The stress to reach carbon peaks varies considerably from region to region, and the stress in the northwest is much higher than that in developed eastern China. Considering the heterogeneity of carbon peaking stress, additional concerns should be given to the net embodied carbon output in the northwestern, northern, and central regions, which can help avoid the dilemma between outsourcing embodied carbon and reducing carbon emissions from production. The policy to reduce emissions should be implemented in all regions that benefit from the net embodied carbon output of the northern and northwestern regions, where the carbon peaking stress is higher. The focus should be on the actual improvement of the carbon peaking stress, not just on the transfer of stress. The increasing urgency of achieving carbon peaking targets and unequal stress for regional peaking emissions calls for differentiated regional mitigation measures to help the Chinese government scientifically and in an orderly manner promote the overall and local carbon peaking work. Full article

The construction sector is achieving its goal of decarbonization. Bioproducts are known to reduce the environmental footprint of the building process, but it is necessary that we determine their exact environmental value. However, assessing the environmental impact relating to buildings is challenging due to a lack of data. The objective of this study was to generate background datasets contextualized to Pinus sylvestrys, L. glulam manufacturing in Spain and apply those datasets to a cradle-to-gate life cycle assessment (LCA) to evaluate both embodied energy (EE) and carbon (EC), as well as biogenic carbon and emissions to air. The corresponding raw materials and energy flows required to apply the LCA methodology were gathered and processed from information from the Spanish forest and wood industry. The resulting background datasets include 27 vehicles and machines, which allowed the quantification of four impact category indicators: renewable primary energy (resources), non-renewable primary energy (resources), use of renewable secondary fuels and global warming potential. Biogenic carbon was also calculated. Based on those five values, the embodied energy and carbon of Pinus sylvestris, L. glulam were quantified: EE = 1401 MJ/UD and EC = −724 kg_CO2-eq/UD. The generation of background datasets and environmental information is innovative and of great interest, and it is a powerful tool for prescribers and technicians. Full article

The embodied carbon of building materials is a significant contributor to greenhouse gas (GHG) emissions. Hemp is widely acknowledged as the most used vegetal insulation in building and construction due to its comparable thermal properties and better environmental performance than that of mainstream insulation materials (MIMs). However, the application of hemp insulation materials (HIMs) in Canada is still in its infancy. Canada is currently the largest hemp oil and seed producer in the world. Most recent research on hemp in Canada has focused on the impact of legalising marijuana and the popularisation of hemp health products and cannabidiol (CBD). There is a lack of studies addressing the holistic impact of hemp in reducing emissions in Canadian residential buildings. This paper exams the feasibility of large-scale hemp cultivation in Canada and the suitability of HIMs for Canadian private dwellings. Material flow analysis (MFA) and life cycle assessment (LCA) were applied to evaluate different levels of carbon mitigation over time produced by HIM substitution. The results show that Canada has sufficient farmland and perfect geographic location and weather to implement large-scale hemp cultivation. HIM substitution can be accomplished for 81% of Canadian residential buildings. Full HIM substitution fulfilled through 5% hemp fibre insulation (HF) and 95% hempcrete (HC) will mitigate 101% of the GHG emissions caused by existing MIMs and contribute up to a 7.38% reduction in emissions to achieve the net zero emissions target by 2050. Full article

The rationalization of material flows, together with the utilization of waste raw materials for the production of alternative binders, became a very attractive topic during the last decades. However, the majority of designed materials can be used as a replacement for low-performance products. In this work, the waste materials (brick powder and blast furnace slag) are valorized through geopolymerization to design high-performance material as an alternative to high-performance concrete. Designed mixtures activated by sodium silicate and waste-originated alkali solution are characterized by the meaning of the chemical and mineralogical composition, evolution of hydration heat, and mechanical strength test. To contribute to the understanding of the environmental consequences and potential benefits, the carbon footprint and embodied energy analysis are provided. Obtained results highlight the potential of end-of-life bricks for the design of high-performance composites if mixed together with more reactive precursors. Here, even values over 60 MPa in compressive strength can be achieved with the dominant share of low-amorphous brick powder. The higher crystalline portion of brick powder may lead to the reduction of drying shrinkage and preservation of flexural strength to a greater extent compared to used slag. Performed environmental analysis confirmed the CO₂ emission savings; however, the embodied energy analysis revealed a huge impact of using alkaline activators. Full article