Understanding how societies accept new transport fuels is a central challenge for interdisciplinary transitions toward sustainable energy systems, being crucial for mitigating climate change and reducing global greenhouse-gas emissions. Because transport sectors are a major consumer of fossil fuels, social-science perspectives on alternative energy carriers, particularly biofuels, have become increasingly important for interdisciplinary transport research. Biofuels can contribute to lower emissions and reduced dependence on finite resources. Their deployment remains contested in social-science debates concerning environmental trade-offs, land-use change, food security and equity within transport systems. Elucidating social determinants of acceptance is essential for informing interdisciplinary transport policy and designing socially robust sustainable-energy strategies. We apply and empirically validate the Technology Acceptance Framework (TAF) to biofuels, linking transport-technology research with the broader social-science literature on technology adoption and sustainability transitions. Using survey data (N = 304) and Partial Least Squares Structural Equation Modeling (PLS-SEM), the framework explained substantial proportions of the variance in acceptance. The analysis confirmed core assumptions of the TAF while revealing important deviations for biofuels. Attitude toward biofuels plays a central role, with additional influences from personal norms, perceived behavioral control, and knowledge. These results highlight that acceptance emerges from the interplay of individual attitudes, personal norms, perceived behavioral control and knowledge, key constructs in social-science theories of transport behavior. Interdisciplinary policy and communication strategies addressing fairness concerns, equity in transport, and public knowledge are required to increase acceptance and support a socially inclusive sustainable-energy transition, providing actionable insights for transport-policy design and ongoing mobility transitions toward low-carbon fuels.

Innovative energy carriers, such as solar fuels, are essential for decarbonizing hard-to-abate mobility sectors and industrial processes. Social acceptance is pivotal for the implementation and scaling of solar fuels, influencing policy feasibility and market uptake. However, empirical evidence remains scarce. Conducting an online survey (N = 830), we assess acceptance levels and perceptions in Germany of a hybrid artificial photosynthesis pathway that produces solar isobutanol. Attitudes are moderately favorable, with moderate sociopolitical support and market acceptance, while community acceptance is neutral. Support for solar fuels is highest in freight transport, followed by public transport and aviation, while acceptance is lowest for private car use and industrial solvent applications. Perceived risks are associated with uncertainties for consumers, production, local implementation, and poor sustainability performance. Perceived benefits include fossil fuel substitution, sustainability, local implementation potential, consumer convenience, and consumer sustainability feelings. While the perceived benefit of fossil fuel substitution, interest in solar fuels and their perceived relevance are the main drivers of sociopolitical and market acceptance, community acceptance is limited by risks relating to production and local implementation, among other factors. Acceptance of genetically modified bacteria for fuel production emerges as a key predictor of acceptance across all dimensions. These findings contribute to a deeper understanding of the acceptance of solar fuel and emphasize the importance of multidimensional acceptance modeling. Based on this understanding of acceptance levels, drivers and barriers, socially accepted pathways in the production, deployment and roll-out of solar fuels can be identified and effective communication strategies developed.

Large language models (LLMs) have been increasingly used to simulate socially complex and interaction-driven tasks. However, most existing studies rely on hand-crafted personas. Since persona design strongly shapes how agents interpret context and make decisions, developing empirically grounded agent profiles is a significant aspect in this underexplored research area. To address this limitation, we propose a survey-grounded generative agent-based modeling (GABM) simulation framework that translates real survey respondents into generative LLM agents. The main objective of our framework is to demonstrate how careful persona design enables realistic simulation of decision-making using LLMs for facilitating behavioral experiments. We illustrate the framework's applicability through a case study of mobility policy preference dynamics in Germany, focusing on public support for phasing out new internal combustion engine vehicles, which is part of the European Union's net-zero target. Our benchmark is based on 514 survey respondents, each translated into a natural-language persona, grounded in demographic characteristics, political orientation, mobility behavior, fuel experience, and climate-related attitudes. The simulation goal is to examine how support evolves over time, how agents switch positions across rounds, and how responses differ across survey-grounded personas under changing social and policy contexts.

Life Cycle Assessments (LCA) are a central tool in sustainable product development and environmental communication. However, little is known about how the general public perceives LCA and its role in consumer decision-making. This study explores public awareness, perceptions, and information preferences regarding LCA and its impact categories, and investigates the factors influencing the relevance of LCA-based information in consumer contexts. Addressing this research gap, the presented study employed a mixed-methods approach, commencing with qualitative in-depth interviews (n = 12), which informed the subsequent development of a quantitative survey (n = 158). The survey measured subjective knowledge, perception of LCA, and of nine impact categories, as well as communication preferences for LCA results. In an example for a car purchase decision, important factors for laypeople’s perception have been identified to determine the potential significance of LCA results for consumers. Despite limited awareness of specific impact categories and a general lack of knowledge regarding the general concept of LCA, participants perceived LCA as a valuable sustainability assessment tool. However, LCA was rated as complex and difficult to understand, and many scientifically relevant impact categories (e.g., ecotoxicity, acidification) were unfamiliar and evoked low risk perceptions. LCA results were considered less relevant than other decision factors, such as cost, but were rated higher among participants with a positive perception of LCA. In turn, participants who perceived LCA negatively were less likely to consider its results in purchasing decisions. Environmental information was considered more relevant than LCA results, suggesting a lack of understanding of the methodological basis of sustainability data. Effective communication strategies should connect LCA to consumers’ values and everyday concerns, increase awareness of lesser-known impact categories, and utilize engaging formats to bridge perception gaps. This study explored public perceptions of LCA, its relevance in consumer decision-making and public communication preferences for LCA results. While LCA was viewed positively, a gap existed between favorable attitudes and actual understanding due to perceived complexity and low awareness of key impact categories. LCA results and environmental information were less relevant in consumer purchase decisions compared to criteria like cost. However, those with a positive view of LCA were more likely to consider environmental factors, highlighting the need for targeted, audience-specific communication strategies.

Abstract Background The transition towards sustainable and emission-free driving technologies has focused on decarbonization strategies, with electric vehicles (EVs) as a long-term solution for replacing fossil fuels. As a complementary defossilized short-term solution, e-fuels emerge, particularly by serving as a bridging fuel alternative for existing combustion vehicles. Beyond the development of technical alternatives, the inclusion of social perceptions is necessary to achieve a successful mobility transformation. In this study, we analyze the differences in the risk perception relating to fossil fuels, EVs, and e-fuels among the German public, to investigate the role of affective and cognitive risk perception dimensions and to measure the impact of individual factors such as climate change awareness, institutional trust and innovativeness by using a representative quantitative questionnaire survey (N = 517). Results The results show significant differences across the risk perception relating to fossil fuels, electric vehicles, and e-fuels among German laypeople. Notably, all risk perception ratings were rather low or moderate, whereas EVs were perceived as the riskiest, while e-fuels were considered the least risky. Furthermore, higher climate change awareness was found to be related to a significantly increased fossil fuel risk perception, whereas higher institutional trust was associated with significantly decreased risk perceptions of alternative fuel vehicles, EVs and e-fuels. There was a positive association between risk perceptions of e-fuels and fossil fuels as well as between EVs and e-fuels. However, there was a negative relation between the risk perception of EVs and fossil fuels. In addition, the analysis of risk perception dimensions supports the two-dimensionality of the construct of risk perception, differentiating between emotional, affect-driven and more rational, cognitive risk perception. Conclusions These findings underscore the importance of understanding public perceptions to facilitate the adoption of alternative fuels and driving technologies. Furthermore, it is advantageous to examine the specific factors that influence risk perception with respect to different technologies, as the results indicate differences between the observed drive types.

The ongoing threat of climate change necessitates a comprehensive restructuring of national energy systems, shifting them from a fossil-fuel basis toward low-carbon pathways to achieve substantial reductions in greenhouse gas emissions. In this context, this work examines the effects of national and global events on climate change mitigation policy, taking the German energy transition, also known as “Energiewende” as a case study. By tracing shifts in political discourse, this study examines changing prioritizations among energy policy targets and explores the circumstances that shaped discourse developments during periods of crisis and transformation, as well as the role of key triggers or pre-existing “windows of opportunity” presented by political and social events. The analysis places particular emphasis on specific systemic factors, including the Fridays For Future demonstrations, the 2021 government change, the COVID-19 Pandemic, and the war in Ukraine. Using a mixed qualitative/semi-quantitative discourse analysis of Bundestag plenary sessions from 2017 to 2022, the study evaluates the ongoing relevance of the energy triangle approach’s qualitative targets. The energy triangle retained its focus on the three primary energy policy objectives despite the occurrence of various significant systemic events. However, the relative prominence of these targets changed over time and temporally coincided with major systemic developments. Within the energy triangle approach, security of supply in particular assumed a distinctive role within the evolving discourse framework. Examining Germany’s political discourse provides insight into the dynamics of energy policy debates during periods of crisis and transformation. Furthermore, the study demonstrates how analyzing parliamentary debates can inform comparative assessments of energy policy developments in various European countries and beyond.

The transition to sustainable mobility is a key component of global efforts to defossilize energy systems, with biofuels playing a strategic role alongside electrification. However, public responses to biofuels are heterogeneous and shaped by subjective risk perceptions rather than knowledge alone. This challenges traditional communication approaches based on the knowledge-deficit model and highlights the need for more differentiated, perception-based audience segmentation. Therefore, his study investigates how knowledge, risk perception, and information need jointly structure communication-relevant target groups for biofuel risk communication. We conducted an online survey with N = 508 German laypersons in 2024 to analyze their knowledge levels, information needs, and perceived risks regarding biofuels. Using cluster analysis, three distinct target group segments were identified: "Concerned Curious," "Concerned Avoiders," and "Calmly Curious". The results reveal that knowledge alone is insufficient to explain differences between groups. The Calmly Curious exhibited high information needs but low risk perceptions, while the Concerned Curious reported elevated risk perceptions alongside high information needs. The Concerned Avoiders showed low knowledge and high risk perceptions. Although the clusters did not differ in socio-demographic variables and attitudinal variables, they yielded different patterns of risk- and benefit perceptions. The findings demonstrate that risk communication should be designed explicitly target-group oriented to address the specific beliefs and knowledge needs of each group, particularly those with heightened concerns about biofuels. By systematically including risk perceptions in addition to knowledge variables in the segmentation of target groups, this study provides insights into the interplay between knowledge levels and risk perceptions.

This study explores perceptions and acceptance of two hydrogen applications that hold potential to reduce CO2 emissions: hydrogen fuel cell buses (HFCBs) and hydrogen utilization in the steel industry (HSI). An empirical mixed methods approach is applied, using qualitative interviews (n = 12) to identify perceived risks and benefits and a quantitative survey among the public (n = 228) to further explore these perceptions and their influence on acceptance. Both studies were conducted in Germany. For both hydrogen applications, the public shows low risk perceptions and high benefit perceptions and acceptance. Acceptance is influenced by affective and cognitive risk perceptions, and in some cases by domain-specific risk and benefit perceptions. However, these drivers differ by acceptance type (sociopolitical vs. local) and by application (HFCBs vs. HSI). The findings highlight the importance of investigating different sustainable technologies individually and provide indications for targeted (risk) communication about hydrogen applications.

Introduction Addressing climate change requires both individual behavioral change and corporate transformation, as organizations play a crucial role in a sustainable society. How sustainability in organizations is perceived and implemented, depends on diverse factors such as management practices, communication, individual attitudes, and behaviors of leaders and employees. However, current research only investigates factors that affect the implementation of sustainable development and practices separately. Hence, holistic approaches are required to provide insight into how they affect a company's sustainability efforts.Methods A quantitative online survey with n = 87 employees was conducted in Germany in 2023. The Corporate Sustainability Index (CSI) was developed to indicate the extent to which organizations implement sustainability into their policies and concrete practices. To investigate which factors predict corporate sustainability, we analyzed employee-, management-, and organization-related factors using multiple linear regression analysis.Results Institutionalized responsibility for sustainability was the strongest predictor of the CSI, along with a top-down approach to implement corporate sustainability. In contrast, employees' environmental awareness and their organizational citizenship behavior towards the environment were not related to CSI.Discussion and conclusions Our results stress the importance of leaders with an environmental focus as role models who can drive the transformation towards effective sustainability management in companies. This study offers important insights into the prerequisites for leaders to foster an environmentally responsible culture in their organizations.

Electric vehicles (EVs) will play a key role in the decarbonization of future mobility. However, the integration of bridging technologies, such as e-fuels, is essential. Public risk perception and acceptance can have a significant impact on the integration of these alternative fuel vehicles. An empirical study was conducted to investigate the risk perception and acceptance of e-fuels and EVs. Additionally, potential influencing individual factors such as age, gender, and climate change awareness (CCA) were considered. Data were collected via a representative quantitative online survey (N = 517, German laypersons) in April 2023. Results indicated higher CCA among females and ambiguous results for age. E-fuels were preferred over EVs as an alternative fuel vehicle, with lower affective risk perceptions and higher acceptance. Regression analyses suggested that age, gender, and CCA marginally predicted risk perception and acceptance of EVs, whereas these factors had no significant influence on e-fuels. Recommendations for technical developers, policymakers, and communicators in the context of sustainable mobility are derived.

The transition towards sustainable and defossilized mobility systems relies on public perception and acceptance of innovations like efuels. Understanding the role of risk perceptions and their different dimensions in shaping public acceptance is therefore critical for facilitating the introduction of efuels into mobility systems. A quantitative survey was conducted among a representative sample of 517 German participants to assess their risk perceptions and acceptance of efuels. A Structural Equation Modeling (SEM) approach was employed to analyze the relationships between cognitive, affective, and domain-specific risk perceptions (health, environmental, and financial) and public acceptance of efuels. The analysis revealed low levels of both cognitive and affective risk perceptions as well as positive acceptance levels for efuels. Financial risk perception was more pronounced than health or environmental risk perceptions. Affective and cognitive risk perceptions were found to negatively impact acceptance, with cognitive risk perception showing a stronger influence. Environmental risk perception was negatively associated with acceptance, while health and financial risks showed no significant association. The findings suggest that while efuels are generally accepted, financial and environmental concerns might hinder widespread adoption. Addressing these concerns through targeted communication strategies that combine cognitive (economic, environmental) and affective (health) dimensions is essential for a socially accepted design of sustainable mobility systems.

IntroductionAs integral societal actors, companies must engage in corporate sustainability to address climate change and remain competitive. While many factors influencing corporate sustainability have been identified, little research has analyzed them jointly.MethodsTherefore, this study surveyed corporate sustainability leaders in a mixed-methods approach, utilizing semi-structured interviews (N = 25) and an online survey (N = 108) to assess organizational and individual, leader-related drivers.Results and discussionQualitative results highlighted the importance of leadership in sustainability decisions. Quantitative results showed that perceived corporate sustainability correlated with individual factors (e.g., leaders' environmental behavior), while practical sustainability, measured by the Corporate Sustainability Index, was linked to organizational factors (e.g., company size). Hierarchical multiple regression quantified the relative impact of factors and confirmed leaders' environmental citizenship behavior, company size, and annual revenue as key sustainability predictors. The findings provide valuable guidance for organizations and policymakers to support corporate sustainability transformation by empowering sustainability leaders and smaller organizations.

Background The need for greenhouse gas abatement measures grows as climate change threatens life on earth. Negative emission technologies, such as carbon capture and utilization (CCU), can reduce emissions from the transport sector, particularly aviation. However, the lack of support and low public acceptance can impact the successful introduction of new technologies. This study analyzes the factors that influence acceptance of the single production steps (capture, purification, conversion, and transport of CO2) of production of CO2-based jet fuels to identify acceptance hot spots and potential roll-out barriers.Results In a quantitative survey with n = 543 German respondents, we find that transport of CO2 in comparison with capture, purification, and conversion of CO2 into hydrocarbons is perceived as less acceptable, efficient, and useful, more expensive as well as damaging for the environment and health. Furthermore, product-step specific risk perceptions, as well as benefit and barrier perceptions for CCU mainly predict people's attitude towards the four production steps. A cluster-analysis revealed two groups, "Approvers" and "Sceptics", which were characterized by distinctive perception profiles. Further analysis showed that sustainability (e.g., use of renewable energy) and efficiency (e.g., carbon removal and resource use) were of greater importance to Approvers.Conclusions The study's results suggest the need for further research and information provision to enhance public understanding of the technology and its role as a part of circular economy approaches. Risk perceptions play a central role in determining attitudes towards CCU, which should be considered in future studies and communication strategies. The findings can inform policymakers, industry stakeholders, and communication experts working to promote sustainable aviation fuel technologies.

The transportation sector is a significant contributor to CO2 emissions, necessitating the adoption of alternative drive technologies to achieve decarbonization. This study investigates public perceptions of fossil fuels, e-fuels, and electric drives, with the aim of identifying factors influencing risk perceptions, perceived efficacy in combating climate change, and readiness to use or purchase cars with these technologies. Therefore, a quantitative study using a questionnaire (N = 141) was conducted. The results indicate that e-fuels and electric drives are perceived more positively than fossil fuels. E-fuels were found to have the lowest risk perceptions. Differences in cognitive and affective risk perceptions, as well as in financial, environmental, and health-related risks, were observed across drive types. Car affinity was found to correlate positively with risk perceptions of e-fuels and fossil fuels, but negatively with electric drives. The risk perception of global warming showed an inverse relationship. Regarding the prediction of readiness, differences were found between e-fuels and electric drives in terms of the influencing factors on readiness. The study contributes to the understanding of public perceptions by providing a comparison between different drive technologies and offers valuable insights for developing targeted communication strategies.

Direct Air Carbon Capture and Storage (DACCS) is a climate change mitigation approach whereby CO2 is collected and concentrated from the atmosphere for permanent storage. Public awareness and understanding of DACCS are limited, which may result in the formation of inadequate mental models, misconceptions and heightened risk perceptions. This study therefore assessed and evaluated the mental models and risk perceptions of DACCS among laypeople and experts, with the aim of informing effective risk communication. Qualitative interviews (n = 12) were conducted with laypeople and experts to identify key characteristics of mental models of Direct Air Carbon Capture and Storage. This was followed by a quantitative survey of 177 German laypeople to assess mental model characteristics, risk perceptions, subjective knowledge, and trust. The results indicated that laypeople's mental models were less complete, less accurate, and less specific than the expert model. Furthermore, less elaborate mental models were associated with lower subjective knowledge levels, partly higher risk perceptions, and lower trust levels. Based on these findings, recommendations for risk communication design were derived from the discrepancies between lay and expert mental model perspectives. Additionally, suggestions for the application of the mental model approach to the communication of innovative sustainable technologies were provided.

Renewable liquid fuels produced from biomass, hydrogen, and carbon dioxide play an important role in reaching climate neutrality in the transportation sector. For large-scale deployment, production facilities and corresponding logistics have to be established. However, the implementation of such a large-scale renewable fuel production network requires acceptance by citizens. To gain insights into the structure of efficient and socially accepted renewable fuel production networks, we propose a bi-objective mixed-integer programming model. In addition to an economic objective function, we consider social acceptance as a second objective function. We use results from a conjoint analysis study on the acceptance and preference of renewable fuel production networks, considering the regional topography, facility size, production pathway, and raw material transportation to model social acceptance. We find significant trade-offs between the economic and social acceptance objective. The most favorable solution from a social acceptance perspective is almost twice as expensive as the most efficient economical solution. However, it is possible to strongly increase acceptance at a moderate expense by carefully selecting sites with preferred regional topography.

Understanding sustainability behavior is essential in tackling the global challenge of climate change. The importance of studying sustainability practices and their dynamics grows in light of recent global crises such as the COVID-19 pandemic and the energy crisis following the Ukraine war. These events both challenge and shape individual sustainable practices, offering opportunities for fostering individual sustainable practices and enhancing societal resilience. An online survey was conducted in Germany (n = 571, May 2023) to investigate sustainable behavior dynamics (mobility, energy-saving, and shopping habits) and to identify segments reflecting behavioral shifts. We found relative stability in sustainable mobility choices compared to pre-crisis times, with a tendency towards reduction, as well as an overall increase in energy-saving and sustainable shopping habits. Factor analyses revealed that sustainable mobility behavior (SMB) and sustainable consumer practices (SCP) formed two separate domains. Cluster analyses further identified four segments within each domain, each exhibiting unique behavioral patterns compared to pre-crisis practices. Examining individual variables, adopting more sustainable mobility practices was associated with sociodemographic factors (income, education, and area of living), higher levels of environmental awareness, institutional trust, and increased risk perceptions. Sociodemographic variables had less influence on sustainable consumer practices. Here, higher levels of knowledge, climate change awareness, trust, and risk perceptions played a significant role. Our findings highlight the importance of separately considering behavioral domains in understanding crises-induced changes in sustainability practices. Moreover, it is important to consider specific individual factors and to develop tailored interventions and policies to promote sustainable practices during volatile times.

Climate change is a constant global challenge. An approach to help mitigate climate change is carbon capture and utilization (CCU), in which captured CO 2 is reused as raw material for consumer products. Because innovations like CCU are unfamiliar to the general public, their communication is critical for a successful rollout. To date, sustainability innovation research has largely neglected the empirical study of communication. The present study contributes to studying the information and communication needs of laypeople based on perceptions and acceptance patterns for CCU by focusing on acceptance profiles for CCU-based insulation boards. In an empirical two-step approach, a qualitative interview prestudy was followed by a quantitative questionnaire measurement ( N = 643). Using k-means clustering, the respondents were divided into three acceptance groups: rejecters (15%), tentative accepters (51%), and strong accepters (34%). Analysis showed that regarding their demographics and personality traits, tentative accepters and rejecters were similar. All segments trusted science and health experts best, and only the rejecters distrusted some specific actors. Information on the product’s risks and functional properties was most important for all acceptance groups. Based on the study’s insights, both general and targeted managerial communication and policy guidelines were formulated.

Professor Jan Mertens is ENGIE's chief science officer (CSO) build-ing ENGIE's long term vision on technologies, identifying key in-ternational research players on selected emerging technologies, and initiating research partner-ships worldwide for the group. Since 2019, Jan is also part-time professor at the University of Ghent in the domain of sustain-able energy. He holds a PhD in environmental engineering from the Katholieke Universiteit Leuven (2006). His main research topics are related to emerging energy technologies, sustainabil-ity assessment including life cycle assessment, emissions moni-toring, carbon capture, carbon use, and water footprinting.

Background Alternative fuels made from biomass or CO 2 and water using renewable energy can reduce CO 2 and pollutant emissions compared to fossil-based mobility and thus support a transition to a more sustainable transport. The adoption of alternative fuels in transport will ultimately depend on public acceptance and drivers’ willingness to use them. Little is known if and under which circumstances people would accept alternative fuels and which narratives and cognitive beliefs might underlie these usage intentions. Moreover, it is unclear if and how laypeople distinguish between different alternative fuel types in their perceptions, e.g., between fuels made from biomass (biofuels) and fuels produced using electricity (e-fuels). To address the research gap, this study empirically investigated laypeople’s beliefs and expectations towards alternative fuels and preferences for different fuel types. Understanding preferences for fuel types could help in steering public information, support managerial decisions and communication pathways, and promote the roll-out process of fuel innovations. Results Laypeople expected alternative fuels to be made using renewable feedstocks and to not contain gasoline or diesel. Whereas alternative fuels were believed to have advantages concerning environmental and toxic effects and safety compared to diesel and gasoline, they were associated with practical disadvantages for drivers. It was shown that although e-fuels and biofuels both fall under the definition of ”alternative fuels”, laypeople distinguish between them in evaluations of safety, costs, and resource competitiveness: E-fuels were preferred over biofuels and believed to have a lower competition for resources than biofuels. They were also evaluated to be more expensive and comparably less safe to use. Moreover, different adopter groups were identified for both fuels. Conclusions The study has highlighted both adoption drivers and barriers for alternative fuels: Reduced environmental impact could be an important positive factor. In contrast, drawbacks feared by laypeople regarding a low range and an expensive fuel price could be barriers for alternative fuel adoption because they reflect current technical challenges for these fuels. Thus, a more cost-efficient production and higher fuel efficiency should be considered in an acceptance-optimized alternative fuel production.