Description: This assessment report identifies six key areas of sustainable consumption. Transforming those areas is associated with a significant, positive impact on sustainable development. In this way, those key areas lay the foundation to set clear priorities and formulate concrete policy measures and recommendations. The report describes recent developments and relevant actors in those six fields, outlines drivers and barriers to reach a shift towards more sustainability in those specific areas, and explores international good-practice examples. On top of this, overarching topics in the scientific discourse concerning sustainable consumption (e.g. collaborative economy, behavioural economics and nudging) are revealed by using innovative text-mining techniques. Subsequently, the report outlines the contributions of these research approaches to transforming the key areas of sustainable consumption. Finally, the report derives policy recommendations to improve the German Sustainable Development Strategy (DNS) in order to achieve a stronger stimulus effect for sustainable consumption.

Description: Effective actions to mitigate climate change are urgently needed, especially in the context of cities, which are major sources of global CO2 emissions. Establishing and managing knowledge systems that integrate local knowledge can contribute to establishing more effective responses to climate change as well as transformative change towards sustainability. However, it is still unclear how new forms of urban governance should acquire, store, create, or disseminate knowledge for fostering sustainability transitions effectively. In this study, we present a multilevel knowledge system approach based on design principles informed especially by the knowledge management literature. These address (i) working environments across multiple levels, (ii) knowledge forms and types, and (iii) knowledge processes. We apply this approach to municipal climate action in the German energy transition. In particular, we focus on the operational work of municipal climate action managers of regional centers of Lower Saxony, one of the largest of the 16 federal states, and investigate their involvement in knowledge processes. Based on semi-structured interviews in 14 of the 17 regional centers, we show that structural pre-conditions for successful knowledge management and organizational learning are present. However, we also show that there is a need for improvement regarding (i) the multilevel coordination for accelerating routine operation, (ii) the persistence of local operational knowledge, and (iii) the exploitation of local innovations. Relying on these results, we offer general recommendations for municipal climate action and suggest that policies should (i) rely on local knowledge for effective decision-making, (ii) foster multilevel exchanges of explicit and tacit knowledge for implementation, and (iii) enable open-ended learning processes that leverage local innovations for creating usable transformational knowledge.

Description: In this paper, we aim to present a comprehensive analysis on the emerging phenomenon of distributed innovation in commons-based peer production (CBPP) platforms. Starting with the exploration of the widely held belief on value-creation confined to industrial settings, we raise several questions regarding the feasibility of, and a need for, an inclusive innovation process that can tap grassroots capacity into both traditional (industrial research and development) and emerging (peer-to-peer) innovation models to yield sustainable solutions. In particular, we explore the emergence and structuration of digital innovations in the maker movement, as it presents an alternative construct of innovation wherein access to and sharing of knowledge is predominantly distributed. With innovation outcomes often freely revealed, its very structuration could pose a principal challenge to our conceptualizations of value creation and competitive advantage in the current economic model. Drawing from responses received from 200 collaborative innovation platforms, six semi‐structured interviews focusing on socio-technical innovation cases, as well as four in-depth narrative interviews with maker turned entrepreneurs, we present a detailed analysis on the topology of network, typology of actors, as well as the underlying innovation ecosystem in CBPP networks in Germany. In doing so, we contribute to the conceptualization of peer-to-peer distributed innovations in collaborative platforms.

Description: Background: Facing planetary boundaries, we need a sustainable energy system providing its life support function for society in the long-term within environmental limits. Since science plays an important role in decision-making, this study examines the thematic landscape of research on sustainable energy, which may contribute to a sustainability transformation. Understanding the structure of the research field allows for critical reflections and the identification of blind spots for advancing this field. Methods: The study applies a text mining approach on 26533 Scopus-indexed abstracts published from 1990 to 2016 based on a latent Dirichlet allocation topic model. Models with up 1100 topics were created. Based on coherence scores and manual inspection, the model with 300 topics was selected. These statistical methods served for highlighting timely topic trends, differing thematic fields, and emerging communities in the topic network. The study critically reflects the quantitative results from a sustainability perspective. Results: The study identifies a focus on establishing and optimizing the energy infrastructure towards 100% renewable energies through key modern technology areas: materials science, (biological) process engineering, and (digital) monitoring and control systems. Energy storage, photonic materials, nanomaterials, or biofuels belong to the topics with the strongest trends. The study identifies decreasing trends for general aspects regarding sustainable development and related economic, environmental, and political issues. Conclusions: The discourse is latently adopting a technology-oriented paradigm focusing on renewable energy generation and is moving away from the multi-faceted concept of sustainability. The field has the potential to contribute to climate change mitigation by optimizing renewable energy systems. However, given the complexity of these systems, horizontal integration of the various valuable vertical research strands is required. Furthermore, the holistic ecological perspective considering the global scale that has originally motivated research on sustainable energy might be re-strengthened, e.g., by an integrated energy and materials perspective. Beyond considering the physical dimensions of energy systems, existing links from the currently technology-oriented discourse to the social sciences might be strengthened. For establishing sustainable energy systems, future research will not only have to target the technical energy infrastructure but put a stronger focus on issues perceivable from a holistic second-order perspective.

Description: At the heart of transition research lies the question of how to "scale up" sustainable alternatives from a protected niche to the creation of mainstream practices. While upscaling processes are often seen as an essential element that contributes to societal transformation, upscaling itself remains a fuzzy concept. We argue that some fundamental dilemmas of upscaling can be identified, for example, the different understanding of the concept by researchers and practitioners. The dilemmas should be addressed in a more reflexive way by those from the worlds of science and practice who are involved in collaborative research settings.

Description: Businesses like Airbnb have shown that a successful circular economy (CE) business can operate exclusively online. Although online communication and web appearance attributes have been subject to academic research given accelerated digitization, there is still a lack of knowledge about online attributes and their role in facilitating CE. We close the portrayed knowledge gap by conducting a discrete-choice experiment with best to worst scaling and focusing on the effect of CE experience on the perception of a CE website by ranking nine online attributes, grouped in three subsets. We therefore contribute by identifying online attributes that are perceived as favorable for CE businesses and detect how participation in CE activities affects the perception of these attributes. We find that third-party associated online attributes (e.g., user reviews or third-party guarantees) rank significantly higher throughout CE consumption patterns of the sample, being always amongst the top three attributes. This novel finding on online preferences opens a new direction for further research, as well as allows practitioners to optimize online operations accordingly. Furthermore, we find that users without prior touchpoints with CE have a higher need for information about the business model as compared to CE active users who are more interested in community related attributes.

Description: Quantitative environmental assessments are crucial in working effectively towards sustainable production and consumption patterns. Over the last decades, life cycle assessments (LCA) have been established as a viable means of measuring the environmental impacts of products along the supply chain. In regard to user and consumption patterns, however, methodological weaknesses have been reported and, several attempts have been made to improve LCA accordingly, for example, by including higher order effects and behavioural science support. In a discussion of such approaches, we show that there has been no explicit attention to the concepts of consumption, often leading to product-centred assessments. We introduce social practice theories in order to make consumption patterns accessible to LCA. Social practices are routinised actions comprising interconnected elements (materials, competences, and meanings), which make them conceivable as one entity (e.g. cooking). Because most social practices include some sort of consumption (materials, energy, air), we were able to develop a framework which links social practices to the life cycle inventory of LCA. The proposed framework provides a new perspective of quantitative environmental assessments by switching the focus from products or users to social practices. Accordingly, we see the opportunity in overcoming the reductionist view that people are just users of products, and instead we see them as practitioners in social practises. This change could enable new methods of interdisciplinary research on consumption, integrating intend-oriented social sciences and impact-oriented assessments. However, the framework requires further revision and, especially, empirical validation.

Description: This paper explores how the European Commission promotes the concept of Sustainable Urban Mobility Planning (SUMP) among European cities. Despite the strong uptake of the SUMP concept, mobility-related problems persist in European municipalities. Linking theoretical approaches to understand the diffusion of policies with empirical findings from working with cities in the SUMP context, this article explores channels of policy diffusion and investigates shortcomings related to the respective approaches. Studies on the diffusion, the transfer and the convergence of policies identify formal hierarchy, coercion, competition, learning and networking, and the diffusion of international norms as channels for policy transfer. The findings which are presented in this paper are twofold: First, the paper finds evidence that the Commission takes different roles and uses all mechanisms in parallel, albeit with different intensity. It concludes that the approaches to explain policy diffusion are not competing or mutually exclusive but are applied by the same actor to address different aspects of a policy field, or to reach out to different actors. Second, the article provides first evidence of factors that limit the mechanisms' abilities to directly influence urban mobility systems and mobility behaviour.

Description: The decarbonisation of the building stock is an important element for the success of the German Energiewende (energy transition). Despite some progress having been made, the rate of energy renovation falls below the level required to meet political commitments. This gives rise to the question: what deters property owners from making energy efficiency investments and how can the policy framework foster such investments? To answer this question, the paper focuses on a widely neglected property owner group: small private landlords (SPL). Although they manage 37% of all residential rental properties in Germany, very little is known about their decision-making processes for energy efficiency investments. We applied a mixed-method design to identify factors that hindered and supported their investments. In an explorative study, we initially conducted 18 problem-centred interviews. Subsequently, we carried out a postal survey and analysed the questionnaires using a hierarchical linear regression model. The results show that energy renovation is a multi-dimensional decision-making process, which can only be adequately addressed by a comprehensive policy package. To develop such a package, the author recommends that the specific investment behaviour of SPL must be better targeted, their knowledge about energy efficiency investments must be improved through exchange and networking, a sense of responsibility for the neighbourhood must be fostered, and greater focus must be placed on improving local framework conditions