Bio-methanol is emerging as a practical low-carbon fuel for the decarbonization of the international shipping sector. Its production relies on the efficient conversion of biomass into syngas. Therefore, this study proposes a bio-methanol production process employing catalytic pyrolysis as the main syngas production step. Specifically, CO2-assisted catalytic pyrolysis was employed because of its higher syngas productivity than conventional catalytic pyrolysis, as reported previously. Building on this approach, three strategies were developed with distinct syngas production routes: Strategy A (catalytic pyrolysis in N2 condition), Strategy B (catalytic pyrolysis in CO2 condition), and Strategy C (integrating biogas reforming with CO2-assisted catalytic pyrolysis). Subsequently, comprehensive energy, economic, and environmental (3E) analyses were performed. The levelized cost of the product (LCOP) of bio-methanol in Strategies B (677 USD/ton) and C (574 USD/ton) was lower than that in Strategy A (830 USD/ton), confirming the economic benefit of CO2-assisted catalytic pyrolysis. Particularly, Strategy C achieved the lowest LCOP, indicating that integrating biogas reforming further improves the economics of bio-methanol production. The sensitivity and uncertainty analyses confirmed the economic reliability of Strategy C, with the LCOP of its bio-methanol comparable to the commercial bio-methanol (320–740 USD/ton). Furthermore, the life cycle assessment (LCA) demonstrated that the bio-methanol produced via Strategy C was environmentally-benign. Overall, these findings highlight Strategy C as a promising option for sustainable bio-methanol production and a viable pathway toward the decarbonization in the international shipping sector.
Higher education institutions (HEIs) are increasingly exposed to climate-related risks, including extreme weather events, infrastructure disruptions, and related social and economic impacts. At the same time, they are expected to play a leading role in advancing sustainability and decarbonisation efforts. In this context, this paper aims to assess how HEIs are preparing to become climate-proof and to identify the institutional strategies, barriers, and priorities that shape the transition towards climate-resilient and sustainable higher education. Adopting a mixed-methods approach, the research combines comparative case studies of universities implementing climate adaptation and mitigation measures with a global online survey of 404 respondents from 83 countries, making it one of the largest studies on the topic undertaken to date. The case studies show three main typologies of institutional response, i.e., comprehensive integration, operational emphasis, and social–educational engagement, illustrating varying levels of maturity and coordination. The survey findings reveal that although more than half of assessed institutions have initiated inventories or decarbonisation strategies, implementation remains fragmented. Operational measures concentrate on energy systems and waste management, while systemic integration across curricula, governance, and community engagement is less common. Key barriers include limited financial capacity, fragmented institutional priorities, and insufficient stakeholder participation. The study shows that climate-proofing higher education requires transformative and cross-sectoral governance, aligning decarbonisation, education, governance and equity objectives.
Sustainable viticulture requires balancing competing economic, environmental, and social objectives, yet comprehensive tools for holistically evaluating alternative management strategies remain limited. This study addresses this gap by developing a multi-dimensional evaluation framework based on Multi-Criteria Decision Analysis using the Analytic Hierarchy Process (MCDA-AHP) to aggregate heterogeneous sustainability indicators into a unified evaluation structure. The framework is tested in a case study from the Rheingau Valley, comparing organic and conventional wine production systems across six sustainability indicators and multiple stakeholder groups. Indicators were selected based on their ability to represent key sustainability aspects while remaining feasible for practical implementation in operational decision-making. AHP results showed that, despite variations in individual preference intensities, stakeholder groups displayed distinct weighting patterns reflecting differences in their sustainability priorities. Institutional stakeholders and academic researchers assigned high importance to economic performance and producers and academic researchers also place high importance on human health risks. Environmental criteria, particularly carbon footprint, received comparatively lower weights across most groups. Across all stakeholder groups, organic production is consistently preferred over conventional production but the overall difference between scenarios is small. This stable ranking reflects the slightly better performance of the organic system in five of six indicators and the limited differences between the assessed systems. The case study serves to demonstrate the operational feasibility of the MCDA-AHP framework and the selected indictors and does not aim to provide a generalized comparison of organic and conventional viticulture. Overall, the findings underscore the importance of incorporating diverse stakeholder inputs when developing tools for holistic sustainability assessments.
While sustainable transport is increasingly called for in urban environments to address congestion and pollution, the uptake of environmentally friendly modes of transport is still low because of implementation challenges and low incentives. Gamified green travel applications address this gap by integrating points, badges, challenges, and rewards into travel planning. In this study, the authors integrate the Theory of Planned Behavior (TPB) and the Technology Acceptance Model (TAM) and examine the intention of the passengers to use such apps. The study uses a survey data collected from urban residents to examine relationships between perceived usefulness, perceived ease of use, attitude, subjective norms, perceived behavioral control, enjoyment, incentives, and adoption intention, using structural equation modelling. The results indicate that perceived usefulness and ease of use improve attitudes and enjoyment and incentives improve perceptions. Gamification indirectly benefits adoption through usefulness and enjoyment, and social norms and behavioral control play a pivotal role in explaining adoption, which is in line with the integrated TAM–TPB framework.
Excess macroalgal blooms represent a persistent waste-management challenge in coastal aquaculture systems. Therefore, developing low-input, resource-efficient strategies that prevent waste accumulation while recovering value from nuisance biomass is a key objective of cleaner production. Here, we evaluate trophic bioconversion as a resource-recovery pathway by testing whether an herbivorous fish can convert nuisance macroalgal biomass (Ulva prolifera) into marketable seafood while mitigating water-quality risks associated with algal decomposition. Juvenile orange-spotted spinefoot (Siganus guttatus) was used as a model species to assess the feasibility and functional consequences of macroalgal-based feeding. The fish were fed either formulated feed or U. prolifera in a 90-day controlled experiment, complemented by a 98-day field-based assessment of macroalgal dynamics and water quality. Growth performance, digestive morphology and enzyme activities, antioxidant responses, tissue-specific nutrient composition, and ecosystem-level responses were evaluated. Compared with formulated feed, macroalgal feeding supported high survival and sustained growth, although at lower rates, indicating that U. prolifera can meet basic nutritional requirements under low-input conditions. This dietary regime induced pronounced digestive adaptation, including intestinal expansion and a redistribution of enzyme activities, with elevated amylase activity reflecting adaptation to a carbohydrate-rich, low-lipid diet. At the physiological level, macroalgal feeding enhanced primary antioxidant defenses without a parallel increase in downstream detoxification pathways, indicating a selective and efficient stress-response strategy. At the product level, macroalgal-derived nutrients were preferentially allocated to edible muscle rather than nonedible tissues, resulting in a high-protein, low-fat profile and enrichment of nutritionally valuable ω-3 polyunsaturated fatty acids. At the system level, active grazing by S. guttatus accelerated macroalgal removal and altered nutrient dynamics, reducing the risk of secondary nutrient release during algal decomposition. This study provides empirical evidence for a low-input trophic bioconversion pathway that transforms nuisance macroalgal biomass from an environmental liability into a productive aquaculture resource, thereby enhancing resource-use efficiency and supporting cleaner and more circular aquaculture systems.
