Search Results (501)

The reconstruction of detrital flux, paleoclimate, paleosalinity, paleo-primary productivity, paleohydrodynamic conditions, and paleo-water depth enhances understanding of sedimentary processes and their drivers during deep-time greenhouse-icehouse transitions, such as the Eocene–Oligocene transition. This study uses detailed geochemical analyses of major oxides and trace elements in sediment samples collected from the Beni Suef Formation (Bartonian–Priabonian) and the Maadi Formation (Priabonian) in the southern Tethys shelf (Egypt, northeastern Desert). Detrital proxies, including Si/Al, Ti/Al, and Zr/Al, indicate an enhanced influx of terrigenous sediments in the middle portion of the Qurn Member of the Beni Suef Formation, as further supported by noticeable facies variations, particularly the transition from shale to coarser silt- and sand-sized fractions. Paleoclimate indicators (Sr/Ba, Rb/Sr, K₂O/Al₂O₃, and Sr/Cu) point to a climatic shift from humid to arid conditions, consistent with the regional Late Eocene aridification across the Tethyan realm. Paleosalinity proxies (Sr/Ba, Ca/Al, and Mg/Al×100) suggest episodic intensification of open-marine influence and a reduction in freshwater input, with an upsection increase in Sr/Ba ratios, reflecting phases of enhanced marine water settings or decreased terrestrial runoff. Primary productivity was evaluated using multiple geochemical proxies, including P, Ni/Al, Cu/Al, P/Al, P/Ti, and Babio ratios. These collectively indicate generally low primary productivity interrupted by intervals of enhanced paleoproductivity or increased organic matter export to the sediments. This interpretation is further supported by the low total organic carbon (TOC) values. These results highlight the sensitivity of the southern Tethys shelf to Middle–Late Eocene climatic variability and the key role of prevailing paleoenvironmental conditions in controlling sediment supply, water chemistry, and biological productivity. Full article

Global data center electricity demand is projected to double to 945 TWh by 2030, yet no optimization framework jointly sizes renewable generation, battery storage, hydrogen export infrastructure, and flexible computing loads within a single industrial hub. This paper develops a two-layer techno-economic workflow for an integrated renewable–hydrogen–data center hub in Yanbu Industrial City, Saudi Arabia. HOMER Pro provides baseline capacity sizing and dispatch across four scenarios; a Pyomo-based mixed-integer linear program, calibrated to within 2% of the baseline, then extends the system to include a 60 MW data center (30 MW critical, 30 MW flexible), multi-sink hydrogen allocation (domestic, ammonia, methanol), and low-grade waste heat recovery. Battery storage emerges as the dominant cost–carbon lever: its removal raises the levelized cost of electricity (LCOE) from 0.052 to 0.181 USD/kWh (+250%) and increases CO₂ emissions from 1.83 to 2763 kt/yr, a factor of 1510. The Integrated Hub reduces annualized costs by 8.2% (36.9 M USD/yr) and emissions by 28% relative to a separate-build counterfactual, driven by shared PV–battery infrastructure and hydrogen export revenues of 58.5 M USD/yr. Export demand raises the electrolyzer capacity factor from 8.65% to 24.3%, cutting the levelized cost of hydrogen from 10.5 to 6.8 USD/kg. Waste heat recovery reduces the levelized cost of heat by 17%, and co-location lowers the levelized cost of compute by 23% (from 0.055 to 0.042 USD/GPU/hr). These results provide quantitative design principles for industrial hub planners considering data center co-location in high-solar regions with hydrogen export ambitions. Full article

This study compares two policy instruments for decarbonizing China’s seafood exports to the EU and UK over 10 years using a recursive dynamic computable general equilibrium model. One instrument applies tariff-like carbon surcharges on embedded emissions at the border. The other recognises certified low-carbon production through tiered rate reductions or exemptions. The model constructs product-level carbon cost wedges for processing electricity, aluminium packaging, and cold-chain operations, then transmits them to border prices through pass-through and to import volumes through Armington demand. These mechanisms operate inside a dynamic setting with capital accumulation, learning, and technology adoption. We evaluate processed tuna, shrimp, whitefish, and fresh tilapia to reflect differences in energy use, packaging intensity, and cold-chain reliance. Results show that certification, especially when paired with targeted domestic green finance or tax offsets, speeds adoption of cleaner power and refrigerants and preserves market share better than uniform surcharges. Effects differ between coastal and inland production hubs, supporting location-specific policy bundles. Sensitivity analysis varies carbon prices, adoption speeds, and certification coverage within stated parameter ranges. We report trade, export revenue, emissions, investment, and welfare outcomes and identify product and channel drivers of exposure. Full article

The technological revolution and industrial transformation led by digital technologies are driving the shift from global value chains (GVCs) to digital global value chains (DGVCs). To address the challenge of global climate change while achieving economic growth, many countries are prioritizing practical energy-saving and emission reduction measures, while simultaneously seeking greater trade gains through participation in digital GVCs and the international division of labor. This study examines whether participation in DGVCs reduces carbon emissions. Using balanced panel data covering 62 countries from 2007 to 2021, we employ a Panel Smooth Transition Regression (PSTR) model to investigate the nonlinear relationship between DGVC participation and CO₂ emissions embodied in digital exports (EEDE). The empirical results reveal an inverted U-shaped relationship, indicating that DGVC participation increases emissions below a digitalization threshold but reduces emissions beyond this threshold. These findings provide new evidence for the dual role of digitalization in shaping trade-related emissions and highlight the importance of stage-specific strategies. Policy implications emphasize that less-digitized economies must prioritize breaking free from carbon lock-in by pursuing green transformation alongside digital expansion. The study deepens the understanding of the trade–environment nexus in the digital era and provides actionable insights for aligning digital economic development with global climate goals. Full article

Under the background of the “dual carbon” strategy and regional coordinated development, the synergistic evolution of low-carbon logistics, regional economy, and ecological environment in the Yellow River Basin has become a key pathway to achieving high-quality development. Taking nine provinces (autonomous regions) within the basin as the study area, this paper constructed a coupling coordination evaluation index system for the LREES (Low-carbon Logistics–Regional Economy–Ecological Environment System), and measured the comprehensive development level of each subsystem using the entropy weight method. Based on the coupling coordination degree model, the temporal evolution of the three systems from 2010 to 2024 was systematically evaluated. In addition, global and local spatial autocorrelation models were introduced to identify spatial clustering patterns, while the obstacle degree model was used to identify key constraints at both the criterion and indicator levels. The results revealed that: the overall development level of the LREES systems steadily increased, with reduced regional disparities; the coupling coordination degree showed a trend of “fluctuating rise–gradual coordination,” with the average value increasing from 0.450 to 0.623, indicating continuously enhanced synergy; spatially, a gradient pattern of “downstream > midstream > upstream” emerged, accompanied by significant positive spatial autocorrelation; resource endowment and development scale were major constraints, while construction level, operational efficiency, and governance capacity were secondary. High-frequency obstacle indicators included per capita water resources, total import and export volume, and urban sewage treatment capacity. These findings offer theoretical support and policy guidance for promoting green transformation, enhancing system synergy, and advancing coordinated regional development in the Yellow River Basin. Full article

Choline is an essential nutrient whose physiological importance has not yet been sufficiently recognized by many European nutrition authorities. Despite convincing evidence of its crucial role in liver lipid export, one-carbon metabolism, cell membrane integrity, and nervous system development, explicit dietary recommendations for choline are still lacking in most European countries. In contrast, its importance has long been recognized in the national guidelines of the United States, Australia, China, and other regions. The current and rapidly spreading dietary shifts toward plant-based and vegan diets—characterized by a lower proportion of animal foods, the main sources of choline—increase the risk of suboptimal intake in broad segments of the population. Given the considerable interindividual differences in endogenous choline biosynthesis, which are influenced by sex hormones, physical activity, nutrient interactions, and genetic polymorphisms, adequate dietary intake is essential to meet physiological needs, especially during periods of increased demand such as pregnancy, lactation, and high-performance sports. This narrative review summarizes the evidence for the essentiality of choline, outlines the rationale for deriving intake recommendations for different life stages, and identifies an urgent need for coordinated action by European nutrition societies to address the growing risk of population-wide undersupply. Full article

China’s export-oriented economic expansion has substantially influenced transport-sector CO₂ emissions, raising critical concerns about the environmental impacts of sustained industrial growth and global trade integration. Understanding the interplay between macroeconomic dynamics, trade composition, and industrial structure is essential for aligning economic development with climate mitigation objectives. This study examines transport-related CO₂ emissions in China over the period 1990–2023, employing a hybrid methodological framework that combines econometric modeling—including Autoregressive Distributed Lag (ARDL) bounds testing, Fully Modified Ordinary Least Squares (FMOLS), and Dynamic Ordinary Least Squares (DOLS)—with machine-learning techniques using Extreme Gradient Boosting (XGBoost) interpreted through SHapley Additive exPlanations (SHAP). The analysis confirms a long-run cointegration relationship between transport emissions and the selected macroeconomic variables. Short-run dynamics indicate a strong sensitivity of emissions to GDP growth, while long-run estimates reveal that higher export-to-GDP ratios and industrial value added contribute to reducing transport emissions, reflecting the efficiency gains from industrial upgrading and cleaner trade practices. By contrast, the expansion of medium- and high-technology exports increases emissions due to the energy- and logistics-intensive nature of high-value goods. The XGBoost model achieves high predictive performance, with an out-of-sample R² of 0.9975 and a Root Mean Square Error (RMSE) of 87.16, confirming the dominant contribution of medium- and high-technology exports to transport-sector emissions. The results underscore the critical role of aligning trade structure, industrial productivity, and low-carbon logistics within China’s policy agenda. Implementing strategies that enhance industrial energy efficiency and develop sustainable transport infrastructure can substantially reduce the environmental impacts associated with export-driven economic expansion. Full article

For nations heavily dependent on fossil-fuel exports, hydrogen is emerging as a promising solution to reduce carbon emissions while preserving economic stability and promoting countries’ energy independence. This research study examines hydrogen potential as a renewable energy source to facilitate the transition toward a sustainable economy with a special focus on Middle East and North Africa (MENA) countries. The analysis delves into policy frameworks, technological advancements, and infrastructure adaptations to build a reliable green hydrogen supply chain for a scalable and bankable future. The role played by other renewable energies like solar and wind, together with the risk related to the high demand for water resources to achieve the green hydrogen transition, has also been assessed. Furthermore, key challenges have been highlighted, including the repurposing of the existing pipelines into the energy networks, public–private partnerships to secure investment, and legislation requirements to encourage the adoption of novel hydrogen applications. In order to do that, a SWOT-PESTEL analysis has been carried out to identify the main decarbonization strategies for achieving a replicable framework. Moreover, a multi-criteria decision analysis was performed, applying 11 indicators across supply-side (e.g., solar/wind potential, LCOE, and water stress), demand-pull/logistics (e.g., maritime connectivity, steel production, and LNG export capacity), and risk/regulation dimensions (e.g., governance effectiveness, regulatory quality, and fossil rent dependence). The Analytic Hierarchy Process (AHP) was used for weighting, the entropy method for weighting variability (hybrid 50/50 combined weights), min–max normalization for costs, 5% Winsorization for outliers, and TOPSIS for aggregation following OECD-JRC composite indicator guidelines. Results have been validated through a multiple scenario analysis (base, supply-led, and risk-aware) and sensitivity testing via Dirichlet bootstrapping (5000 iterations) with ±20% weight perturbations. Six countries of the MENA region have been studied. The multi-criteria decision analysis outcomes rank Egypt (composite score 0.518), Algeria (0.482), and Oman (0.479) as the most suitable countries for large-scale green hydrogen and ammonia production/export, while Saudi Arabia, Qatar, and Kuwait achieved lower supply scores in the base case due to higher perceived risks. Full article

Digital services trade is often viewed as a pathway to lower carbon intensity by reducing reliance on carbon-intensive physical trade. However, its environmental benefits may depend critically on the regulatory environments governing cross-border digital interactions. Integrating institutional distance theory with environmental economics, this study examines how regulatory divergence in digital services trade shapes the carbon intensity of international trade. Using bilateral trade data and country-level measures of digital services trade regulations, renewable energy capacity, and environmental policy rigor, we analyze the effects of digital regulatory gaps on carbon emissions embodied in exports. The results show that greater regulatory divergence significantly increases both total carbon emissions and export carbon intensity. The analysis further reveals that the scale effect associated with increased trade volume dominates the technique effect, such that the potential environmental benefits of digitalization are frequently offset by structural inefficiencies and compliance costs induced by regulatory fragmentation. Moreover, exporters’ renewable energy capability amplifies—rather than mitigates—the carbon-intensity-increasing effect of digital regulatory gaps, indicating that institutional misalignment imposes higher environmental opportunity costs on countries with greater low-carbon potential. By contrast, environmental policy rigor in importing countries does not significantly attenuate these effects. Overall, the findings highlight regulatory alignment as a critical condition for realizing the environmental benefits of digital trade. Full article

The ocean constitutes the largest actively exchangeable carbon reservoir in Earth’s surface system, with the ocean–atmosphere system functioning as an integrated entity that modulates atmospheric CO₂ concentrations over geological timescales. While carbonate and organic-rich sedimentary carbon sinks have been the subject of extensive research, their synergistic roles in long-term carbon–climate feedback loops, as well as the degree to which microbial mediation links ocean hydrographic states to basin-scale carbon sequestration efficiency, remain poorly synthesized. Here, we develop a mechanistic framework comprising five intercoupled components: (1) driving factors (tectonic–climatic forcing and anthropogenic analogs); (2) ocean state controls (basin restriction, water column stratification, and redox conditions); (3) microbial processes (microbial carbon pump-mediated transformation of dissolved organic carbon and the modulating influence of microbial carbonate formation); (4) sedimentary carbon sinks (carbonate platforms versus organic-rich shales underpinning organo-mineral stabilization); and (5) Earth system feedback expressions (e.g., carbon isotope excursions and sustained perturbations in atmospheric CO₂ levels). This framework is validated across three contrasting sedimentary basins, including the Western Tethys rift basins, the Cambrian South China platform system, and the Toarcian Lower Saxony restricted basin, and via three falsifiable propositions. Converging evidence from these case studies corroborates three key conclusions: (1) basin restriction and diminished water mass renewal foster water column stratification and hypoxic/anoxic conditions, thereby enhancing organic carbon preservation (P1); (2) the tectonic and depositional setting of a basin modulates the relative predominance of carbonate and organic carbon sinks (P2); and (3) post-extinction anachronistic facies record amplified microbial control over carbon burial pathways (P3). By emphasizing the context dependence of carbon sequestration processes and the significance of organo-mineral stabilization alongside particulate organic carbon export, this synthesis provides a transferable analytical framework for interpreting deep-time carbon cycle transitions and for contextualizing the impacts of modern ocean warming and deoxygenation on natural carbon sinks. Full article

CBAM is reshaping the external conditions under which open economies pursue decarbonization, raising new questions about how domestic carbon pricing can remain effective while supporting sustainability. We develop an environmental DSGE model for a small open economy with a cleaner green sector and an emissions-intensive brown sector, an endogenous green innovation margin, and a banking sector that prices sector-specific transition risk through credit spreads. Carbon pricing affects the economy through relative prices and resource reallocation, while CBAM acts as an export-revenue wedge that weakens cash flows in exposed activities and tightens financing conditions. In the baseline, a coordinated increase in the domestic effective carbon price cuts emissions quickly and shifts investment toward the green sector, with aggregate activity recovering as reallocation proceeds. Under CBAM, the near-term contraction is deeper, and the spread spikes more, but endogenous green innovation and a policy mix that combines targeted green credit support with macroprudential measures deliver a smoother adjustment and the largest welfare gains. The results suggest that coherent policy packages linking carbon pricing, innovation support, and financial stability are central to managing the transition in an open economy. Full article

China has assumed a leadership position in global kelp cultivation and export. However, the kelp harvesting process in China still relies primarily on manual labor, with only limited adoption of semi-mechanized devices. This dependence results in suboptimal efficiency and elevated labor intensity. The industry now faces an acute labor shortage driven by an aging workforce and rising labor costs, highlighting the urgent need for a fully mechanized harvesting solution. This paper comprehensively reviews current research on mechanized kelp harvesting devices for raft cultivation systems in China. It compares domestic and international practices in kelp seedling cultivation, cultivation models, and harvesting devices, with particular emphasis on the technical challenges hindering harvesting device development in China. Based on this analysis, we propose several recommendations, including the simultaneous advancement of cultivation model optimization and harvesting device innovation, the development of harvesting technologies aligned with specific downstream processing requirements, and the design of modular and multifunctional kelp harvesting vessels. Looking ahead, future research should prioritize integrating automation and intelligent systems, reflecting evolving trends in China’s marine aquaculture. Furthermore, to support China’s “dual carbon” goals, future harvesting systems should incorporate carbon-reduction features. Full article

This study explores the reasons why, despite ambitious national strategies, the deployment of renewable energy in Arab countries has persistently lagged behind global trends. It investigates the drivers of this disparity by analyzing the impact of fiscal capacity, energy market size, and energy dependence on renewable energy development. To control for country heterogeneity, this paper divides Arab countries into three groups based on their degree of energy dependence: energy-importing countries, energy-exporting countries, and energy trade reversal countries. Using a panel dataset of 17 Arab countries from 1990 to 2022, this study employs a dynamic common correlated effects (DCCE) estimator, which uniquely accounts for cross-sectional dependence and distinguishes between short-run dynamics and long-run equilibrium. The results reveal three key findings. First, in energy-importing and energy trade reversal countries, improvements in government fiscal balance significantly promote renewable energy development. Second, higher energy consumption exerts a persistent negative effect on renewable energy development, suggesting that demand expansion reinforces carbon lock-in rather than facilitating transition. Third, energy dependence exhibits a temporal asymmetry: it hinders renewable deployment in the short run, but becomes a strong positive driver in the long run, reflecting a shift from immediate supply security to strategic energy security. However, for energy-exporting countries, those drivers are statistically insignificant, highlighting strong path dependence. These findings partly validate the “developmental state”, “carbon lock-in”, and “energy security” theories within the Arab context. The study concludes that fiscal buffers and the pursuit of energy security facilitate the deployment of renewable energy in specific country contexts, while growth in energy consumption reinforces carbon lock-in. These findings contribute to SDG 7 and SDG 13, with particular relevance to Arab countries grappling with the dual challenges of economic diversification and the climate commitments outlined in the Paris Agreement. Full article

Background: Nano- and microplastics (N/MPs) are widespread pollutants in aquatic ecosystems and may interfere with the physiology of diatoms. However, the underlying molecular mechanisms remain poorly understood. Methods: Cultures of the diatom species Skeletonema marinoi, a key contributor to marine primary production and biogeochemical cycles, were exposed for 10 days to polyethylene (PE) N/MPs (25 and 75 µg/mL). Growth, morphology, and cell viability were monitored, while gene expression of stress, inflammation, programmed cell death (PCD), and extracellular polymeric substance (EPS) biosynthesis markers was assessed by RT-qPCR. Results: Growth was not significantly affected. Gene expression showed biphasic regulation of antioxidant enzymes, induction of HSP70/90, transient modulation of prostaglandin-related genes, and dose- and time-dependent activation of PCD markers. Selected CAZymes possibly involved in EPS synthesis were downregulated at early stages, suggesting impaired aggregation potential. Conclusions: Exposure to PE N/MPs elicited subtle yet multifaceted effects in S. marinoi, including oxidative stress, inflammatory-like responses, modulation of EPS pathways, and PCD activation. Despite apparent growth resilience, the molecular alterations observed may impact bloom dynamics and carbon export. Full article

With the accelerated low-carbon transition of the global energy mix, offshore wind power (OWP) is one of the fastest-growing renewable resources and is often integrated with conventional thermal units into a bundled export transmission system. Under sudden large disturbances, the lack of inertia support makes rotor-angle instability prone to occur, which undermines sustainable operation. Battery energy storage systems (BESS) provide fast emergency power support, and an effective control strategy can enhance transient rotor-angle stability while improving operational sustainability. Accordingly, equivalent-circuit models of the regional export system are established for the before-fault, during-fault, and after-fault stages. Building on the extended equal area criterion (EEAC) and the low-voltage ride-through (LVRT) capability of OWP, the stabilizing mechanism of BESS participation is examined from the perspectives of optimal power and timing, thereby yielding an optimal BESS control strategy for improving transient rotor-angle stability in regional renewable export systems. Finally, a regional renewable export system is implemented in MATLAB/Simulink R2022b, where severe contingencies are imposed to validate the effectiveness of the proposed BESS control strategy. Full article