ALBERT

Description: Leftovers are particularly at risk of being discarded, and therefore a main component of household food waste. This study provides insights into sources of heterogeneity in leftover management behaviours, with a particular focus on the use of meal kits providing matched portion and ingredient sizes, and identifies consumer segments via a latent class analysis. We investigate whether belonging to a segment with positive attitudes toward leftovers, and engagement in conscious leftover management behaviours decreases the amounts of dinner leftovers and food waste. Besides, we demonstrate that several food waste antecedents, emotions, personal norms, intention and dinner procurement routines elicit leftover management segment membership. In addition to examining such individual differences, we also investigate the role of meal-level determinants, in particular, whether meal kits heterogeneously affect dinner leftovers depending on the consumer's leftover management segment. Data was collected from 868 households from six countries, using an online survey and diaries. Results of the latent class analysis point towards five consumer segments. We found differences in dinner leftovers amount across classes and detected heterogeneous effects of meal kits. That is, meal kits were able to diminish leftovers in two segments, but not in the other segments. These results provide novel insights into consumer heterogeneity regarding the occurrence, antecedents, and potential solutions of leftovers and resulting household food waste. Implications for both theory and policy are discussed.

Description: As the climate crisis is accelerating and the pressure to act is steadily increasing, many companies are claiming themselves or their products carbon neutral. This is usually achieved by offsetting residual emissions with carbon certificates (carbon offsetting). However, recent revelations about the inadequate quality of carbon credits and legal uncertainties surrounding the use of such offset claims are increasingly raising doubts about this approach. This Wuppertal Report examines how the EU can promote integrity in corporate climate action. Taking into account the new framework of the Paris Agreement, the paper outlines various options for how the EU could push for more integrity and effectively combat greenwashing through the targeted use of Article 6 of the Paris Agreement. In their recommendations, the authors advocate addressing the most serious consequences of ongoing offset practices through increased regulation of offset claims. If a ban on offset claims cannot be implemented, claims requirements and carbon offset regulations should be further specified, for example, by prohibiting any type of double counting of emissions reductions. In addition to tightening the rules for corporate offset claims within Europe, the EU could help partner countries make informed decisions when approving climate change mitigation measures and respective carbon credits. The report also emphasizes the EU's special role in international climate negotiations, where it should advocate for a strong legal framework for climate action under Article 6.

Description: The rise of pedal-assisted bicycles (e-bikes) has the potential to contribute to reducing ubiquitous automobility and its negative externalities on the global climate, mobility justice and the quality of urban life. But what makes this new practice so successful in recruiting new practitioners? What policies can ensure that e-bikes are used in a wide range of situations, thus substituting as much car driving as possible - or even reducing the number of cars? The study focuses on commuting as this use case frequently entails the main obstacles to e-biking in daily routines (e.g., sweat, weather, transporting children or goods). The analysis is primarily based on interviews with practitioners and initially provides a thorough depiction of the practice elements (meanings, materials and competences) involved in e-bike commuting. It furthermore elicits key drivers of and barriers to daily e-bike commuting, points to a number of elements that are important to overcome these barriers and develops two tangible policy approaches to foster the substitution of e-biking for car driving.

Description: Innovative digital technologies open up new opportun­ ities for small and medium-sized enterprises (SMEs) to improve energy efficiency and energy management behavior. The question is: How far will SMEs be capable of profiting from the benefits of these new technologies? Using technology screening, this study identifies smart metering and mobile energy monitoring as digital technologies best addressing SMEs' specific demands. In addition, potentials and limitations of the technologies are investigated in two qualitative in-depth field trials. Barriers to adopting digitally enabled energy management practices are examined. The results indicate that visualising energy data enables SMEs to pursue new energy management practices for reducing energy consumption and costs (such as peak load analysis). SMEs need extensive guidance to identify and pursue these strategies. In conclusion, an exploratory adoption model for digitally enabled energy management practices is developed. Hypotheses for future experimental studies and policy implications are derived.

Description: The steel industry is responsible for a quarter of all industrial greenhouse gas emissions. So far, the environmental savings are mainly due to steel recycling. Besides recycling, the circular economy offers strategies to increase material efficiency and thus decrease the primary raw material demand. However, the potentials remain unexploited because circular economy concepts with a higher degree of circularity are not considered. The presented case study of an industrial machining knife illustrates how the production process can be improved by implementing various circular strategies. The environmental performance is analyzed by calculating and comparing the carbon footprint, the cumulative energy demand and the material footprint, and the material efficiency indicator. The results show that the implementation of the three overarching strategies of the circular economy - narrowing, closing, and slowing - contributes to a significant increase in material efficiency. The implementation also has a positive effect on the overall environmental performance. The circular production processes require less energy and resources and cause fewer emissions. Auxiliary processes such as additional transport routes are relevant, as they can reduce or even overcompensate for savings. These processes must be adequately considered and designed.

Description: The production of green hydrogen in Germany is more competitive than expected compared to imports. This is the key finding of a meta-analysis conducted by the Wuppertal Institute on behalf of the North Rhine-Westphalia Association for Renewable Energies (Landesverband Erneuerbare Energien NRW). The hydrogen study focuses primarily on the year 2030 and beyond - and confirms the advantages of green hydrogen produced in Germany from domestic renewable energies, especially when the evaluation is viewed from a holistic system perspective.

Description: As investors and financial intermediaries, private banks are increasingly confronted with climate change concerns. But to what extent do banks identify as the changemakers driving climate alignment forward? To advance this question, this paper analyzes the South African banking sector with a specific focus on Standard Bank and Nedbank as exemplary case studies. Relying on the concept of "climate mainstreaming", we critically assess the banks' annual reports and compare their self-portrayal with publicly available sources on the bank's business practices, chiefly provided by non-governmental organizations and media. We find that Nedbank pushes a holistic narrative of climate change as an inevitable business opportunity. Standard Bank, in turn, relies on a "narrative of balance" between climate change and other profit-oriented investments to safeguard its stakes in the fossil industry. In so doing, this paper sheds light on greenwashing practices within disclosure specifically and the lack of binding corporate regulation more generally.

Description: Most air-conditioned buildings in India operate as Mixed-Mode Buildings (MMBs), either fully air-conditioned or with natural ventilation depending on the weather. Energy consumption for space cooling is a vital end-use service in buildings. Air-conditioning is expected to increase significantly due to high growth estimates in building construction, sales of Room Air-Conditioners (RACs), and real income growth. Therefore, this thesis examines the most influential design and control parameters that influence the potential of MMBs in India in relation to their thermal and energy performance. The primary features of MMBs analysed in the research project are as follows: shutting windows at night makes night ventilation redundant; natural ventilation through ceiling fans and windows is utilised to maintain optimal thermal conditions in naturally-ventilated mode and RACs are employed in air-conditioned mode. This thesis poses three research questions and aims to answer them. Firstly, what are the research gaps in assessing thermal and energy performance in mixed-mode buildings in India? Secondly, what is their potential concerning key operating conditions, and which parameters affect this potential? Lastly, how can these influential parameters be optimised? To answer these questions, three research methods were employed: 1) literature review; 2) large-scale simulation of building energy performance combined with uncertainty and sensitivity analysis; and 3) field studies of user behaviour with regards to RACs and the impact of ceiling fans and RACs on indoor conditions and energy consumption. The study identifies the cooling set point temperature as the most influential control parameter. In general, input parameters related to building design, shape and geometry were considered more important than those related to construction parameters. Furthermore, the study highlights that a set point temperature of 28 or 30°C is sufficient to maintain indoor comfort according to the Indian Model for Adaptive Comfort (IMAC) for residential buildings. If a specific airflow is required, it would use the least energy to run the ceiling fan at a low speed, usually set at 1.

Description: The COVID-19 pandemic has jolted societies out of normality, possibly creating new conditions for sustainability transformations. What does this mean for sustainability research? Because of the scope of the crisis, researchers have been heavily involved: not only have they had to speed up the pace of scientific production to provide urgently needed COVID-19 knowledge, but they have also been affected citizens. For sustainability science, this calls for an experience-based reflection on the positionality and orientation of research aiming to support sustainability transformations. Twenty sustainability researchers discussed their sustainability research on COVID-19 in three workshops based on the following questions: How does the pandemic - and the measures taken to deal with it - affect sustainable development? What can we learn from the pandemic from the perspective of societal transformation? The present discussion paper emerged from this multidisciplinary exchange among sustainability researchers, considering five topics: impacts of the COVID-19 crisis on sustainability transformations; learning for sustainability transformations; the role of solidarity; governance and political steering; and the role of science in society. Our discussions led to a meta-level reflection on what sustainability research can learn from research on COVID-19 regarding topics and disciplinary angles, time dimensions, the role of researchers, and how adequate preparation for both crises and long-term transformations requires interdisciplinary interaction.

Description: The transition to a greener and more circular economy has been a European policy priority for several years. The Circular Economy Action Plan of 2020 underlines the ambition. The following EEA initiatives are meant to support the transition process: - Bellagio Process on circular economy monitoring principles (EPA network); - Enhancement of EEA indicators on circular economy (ETC/WMGE); - Explorative work on novel data streams (FWC); - Co-creation work - knowledge sharing of monitoring experience (ETC/Eionet). The scope of the present task was to report on the co-creation process that was undertaken at the end of 2020. The co-creation process was organised to identify: (i) best practices on monitoring strategies, data sources and target setting; and (ii) areas of circularity measuring and monitoring that remain challenging and require additional investment. The co-creation process partially built on the work done during the Bellagio Process/Initiative which was run in parallel. This ETC report presents and documents the evidence gathered throughout the co- creation process as well as providing a retrospective analysis of the links to the Bellagio Principles.

Description: "Sustainable Development" can be understood as a widely used discourse that has become even more prominent since the publication of the UN Agenda 2030 for Sustainable Development in 2015. In this paper we analyze the way sustainable development discourse unfolds within the context of development aid in Germany by undertaking a discourse analysis of reports on development policy published 1973-2017 by the German Federal Ministry for Economic Cooperation and Development. Our analysis reveals that the sustainable development discourse is characterized by distinct components and storylines that change over time. We detect, in general, a shift away from a focus on environmental protection toward an emphasis on the role of the private sector in leading sustainable development. We argue, therefore, that although development is now only legitimate if it is "sustainable", the discourse apparently facilitates the uneven allocation of development aid. The concern that arises here is that although Agenda 2030 pledges to take "bold and transformative steps" to secure the planet and to leave "no one behind" the least developed states who cannot provide "private sector opportunities" or fulfil "national self-responsibilities" for sustainable development are indeed being "left behind".

Description: Since the introduction of Germany's first Thermal Insulation Ordinance in the 1970s in response to the oil crisis, requirements for the energy performance of buildings have consistently increased. Today, these are ruled by the German Building Energy Act, which is currently being amended. Despite this continuous tightening of regulations, the energy consumption in German housing has hardly decreased. The continuous increase in residential space per person is a significant reason for this.

Description: The objectives of the urban mobility transition have been clearly set out: gaining more space for urban living, reducing noise and emissions that have a negative impact on the climate and improving air quality. That means less traffic in cities and more trips made using environmentally-friendly modes of transport - i.e., walking, cycling or foot scooters or public transport. In transport policy, the focus is generally on innovative approaches to shaping the mobility transition. This paper aims to explain the concept of exnovation in the context of the urban mobility transition and to underpin it using specific practical examples. In the course of this process, it is intended to identify the obstacles that stand in the way of rolling out the concept on an area-wide basis in order to deduce strategies and courses of action for expanding the concept in the future.

Description: The impending climate catastrophe gives rise to an increased environmental awareness among many designers, who direct their work towards the paradigm of sustainability. While designing with an "ecological lens" is necessarily oriented towards the future, we highlight the past as an inspiring realm to explore. Rather than recycling materials, we encourage the recycling of ideas as a combination of historiographic and speculative design methods. We will present a framework that extends the idea of design as a "projecting" activity into the idea of design as a constant negotiation process about the relevance and appropriateness of current and past technologies. Design revolves not just about what will be, but to a large extent about what should remain and what should recur, or as Jan Michl put it: "seeing design as redesign" (Michl 2002). We will illustrate the thought of designing futures with pasts by means of a research project that aims at developing a refrigerator for circular economy. The refrigerator - as the currently dominant technology to preserve food - will serve as a starting point to show how artefacts and architecture as well as human skills and knowledge in the preparation and preservation of food are historically interlinked. The history of food preservation unfolds not only along the evolution of the refrigerator, but encompasses household techniques like smoking, curing and fermenting, as well as long-forgotten architectural "answers" such as deep-freeze community buildings. We will revisit three historical examples of food preservation and present the method ‘throwing’ past ideas into the future. Three main arguments are presented in this richly illustrated paper: First, that historiography is a form of designing, second, that designing is constituted and influenced by path dependencies (cf. David 1985) that are deeply rooted in the past and third, that the past is a valuable source of inspiration when designing for sustainable development. Looking at history becomes a way of "mental window shopping" (Simon 1985, 188) for approaches that are to be reactivated and transformed.

Description: Four broad categories capture countries' political and economic barriers to quit coal. Use these to tailor solutions.

Description: In his essay, the author presents a stock-taking of the debate on Green Deals. The starting point of this personal assessment is a brief outline of the content and impact of a study in which the author and colleagues published a first outline of a "Green New Deal for Europe" as a political response to the 2008 financial crisis. 2008 had been a critical juncture for mainstream economics: however, from the perspective of policy-learning, the period after has been a lost decade. The European Green Deal as presented by the European Commission in 2019 can be perceived as a historic milestone and confirmation of a regime change in mainstream economic policy in which ecological considerations gain in importance. Yet, the Deal suffers from major deficits. In sum, the European Green Deal could be interpreted as an insufficient attempt to take advantage of the rapidly closing windows of opportunity for a peaceful transition towards sustainability. On the eve of a planetary crisis, the governance of economic transitions towards sustainability needs to be improved and accelerated. Reflecting on the 2009 study A Green New Deal for Europe, this essay attempts to draw a few lessons and frugal heuristics for the policy-design of Green Deals.

Description: At the end of March 2022, the European Commission published its new EU Strategy for Sustainable and Circular Textiles. Its ambitious vision is to reduce textile waste, promote circular measures and minimise the negative environmental impacts of the textile industry. But what would a textile industry that keeps textiles in a closed loop look like, and what political conditions would be required in Germany? This Zukunftsimpuls paper by the Wuppertal Institute points to the role that Germany could play in the transformation towards a circular textile industry.

Description: The food system faces a multitude of challenges, including high greenhouse gas emissions, threats to biodiversity, increased diet-related diseases due to unbalanced diets, and socially problematic complex supply chains. This requires not only a transformation of the agricultural economy but also a change in the diet and lifestyles of all consumers. Developing and using digital and technological innovations can help to solve these challenges. In this context, the study provides impulses on how digitalisation can contribute to transforming production and consumption and which prerequisites have to be given to achieve this. The study describes the approaches for digitalisation along the value chain. These include optimising the use of resources in agriculture - for example with the help of smart farming - and supporting consumers with digital tools and assistance systems - such as apps designed to support grocery shopping. In addition, new business models and a better connection between production and consumption processes are also possible. This includes, for example, new digital sales channels or tracking and communicating sustainability indicators such as CO2 emissions across all steps of the value chain in order to enable all stakeholders to take reliable action.

Description: Research on environmental behaviour is often overlooked in literature on regime destabilization in energy transitions. This study addresses that gap by focusing on socio-political and demographic factors shaping support for carbon regime destabilization policies in one of the most carbon-intensive regions of Europe. Carbon-intensive industries, especially coal mining and coal-based power generation, are often concentrated in a few carbon-intensive regions. Therefore, decarbonization actions will affect those regions particularly strongly. Correspondingly, carbon-intensive regions often exert significant political influence on the two climate mitigation policies at the national level. Focusing on Poland, we investigate socio-political and demographic factors that correlate with the approval or rejection of the two climate mitigation policies: increasing taxes on fossil fuels such as oil, gas, and coal and using public money to subsidize renewable energy such as wind and solar power in Poland and its carbon-intensive Silesia region. Using logistic regression with individual-level data derived from the 2016 European Social Survey (ESS) and the 2014 Chapel Hill Expert Survey (CHES), we find party-political ideology to be an important predictor at the national level but much less so at the regional level. Specifically, voting for right-wing party is not a divisive factor for individual support of the two climate mitigation policies either nationally or regionally. More interestingly, populism is a strong factor in support of increasing taxes on fossil fuel in the carbon-intensive Silesia region but is less important concerning in support of using public money to subsidize renewable energy in Poland overall. These results show the heterogeneity of right-wing party and populism within the support for the two climate mitigation policies. Socio-demographic factors, especially age, gender, education level, employment status, and employment sector, have even more complex and heterogeneous components in support of the two climate mitigation policies at the national and regional levels. Identifying the complex socio-political and demographic factors of climate mitigation policies across different national versus carbon-intensive regional contexts is an essential step for generating in situ decarbonization strategies.

Description: The ecological challenges of this decade have been clearly identified. The pressure of problems is increasing drastically; progress in climate protection or the preservation of biodiversity is insufficient. Little time is left to act. In consequence, we can only achieve and permanently secure social and environmental prosperity through far-reaching changes in economy and society. As a socio-technical innovation, digitalisation can realise its full ecological potential above all where it helps to profoundly change today's lifestyles, consumption patterns, and economic practices with a clear commitment to sustainability. As the most urgent design task of the 21st century, it is important to put digitalisation's enormous creative power at the service of the great transformation. The "great transformation" refers to the comprehensive restructuring of technology, the economy, and society in order to deal with the social and ecological challenges of the 21st century. This is a task for state action in terms of both regulatory policy orientation and facilitating collective processes of change - new tasks call for new governance. A digital-ecological statecraft is the indispensable prerequisite for effective state action to shape the social-ecological digital transformation. Using the example of the platform economy, we explore challenges, starting points, and (policy) measures.

Description: The challenges and also potentials of the energy transition are tremendous in Germany, as well as in Japan. Sometimes, structures of the old energy world need "creative destruction" to clear the way for innovations for a decarbonized, low-risk energy system. In these times of disruptive changes, a constructive and sometimes controversial dialog within leading industrial nation as Japan and Germany over the energy transition is even more important. The German-Japanese Energy Transition Council (GJETC) released a summarizing report for the first project phase 2016-2018. It includes jointly formulated recommendations for politics as well as a controversial dialogue part. The Council jointly states and recommends that: Ambitious long-term targets and strategies for a low-carbon energy system must be defined and ambitiously implemented; Germany and Japan as high technology countries need to take the leadership. Both countries will have to restructure their energy systems substantially until 2050 while maintaining their competitiveness and securing energy supply. Highest priority is given to the forced implementation of efficiency technologies and renewable energies, despite different views on nuclear energy. In both countries all relevant stakeholders - but above all the decision-makers on all levels of energy policy - need to increase their efforts for a successful implementation of the energy transition. Design of the electricity market needs more incentives for flexibility options and for the extensive expansion of variable power generation, alongside with strategies for cost reduction for electricity from photovoltaic and wind energy. The implementation gap of the energy efficiency needs to be closed by an innovative energy policy package to promote the principle of "Energy Efficiency First". Synergies and co-benefits of an enhanced energy and resource efficiency policy need to be realized. Co-existence of central infrastructure and the growing diversity of the activities for decentralization (citizens funding, energy cooperatives, establishment of public utility companies) should be supported. Scientific cooperation can be intensified by a joint working group for scenarios and by the establishment of an academic exchange program.

Description: The German-Japanese Energy Transition Council (GJETC) was established in 2016 by experts from research institutions, energy policy think tanks, and practitioners in Germany and Japan. The objectives and main activities of the Council and the supporting secretariats are to identify and analyze current and future issues regarding policy frameworks, markets, infrastructure, and technological developments in the energy transition, and to hold Council meetings to exchange ideas and propose better policies and strategies. In its second project phase (2018-2020), the GJETC had six members from academia on the Japanese side, and eight members on the German side, with one Co-Chair from each country. From October 2018 to March 2020, the GJETC worked on and debated six topics: 1) Digitalization and the energy transition. 2) Hydrogen society. 3) Review of German and Japanese long-term energy scenarios and their evaluation mechanism. 4) Buildings, energy efficiency, heating/cooling. 5) Integration costs of renewable energies. 6) Transport and sector coupling. The outputs and the recommendations of the second phase of the GJETC are summarized in this report.

Description: The sales of pedelecs are currently skyrocketing in Germany and in many other places. As a low-carbon means of mobility, pedelecs have the potential to make a substantial contribution to the mobility transition. This thesis employs practice theory as proposed by Shove et al. (2012) to investigate this quickly evolving phenomenon. The analysis is based on interviews with e-bike commuters which were investigated using template analysis and exploratory memos. To obtain a broad picture the practice, a maximum variance sampling strategy was carried out in two cities that vary substantially with regard to velomobility: Wuppertal and Münster. This thesis one hand presents the first encompassing account on the practice elements which commuting by pedelec is composed of. It hence contributes to the debate about the depiction of practices. Furthermore, the thesis finds that pedelec commuting should be conceptualized as a variant of velomobility and not as a variant of motoring or as an independent practice. Yet, the elements integrated in pedelec-commuting are found to clearly differ from those of cycling, so that pedelec-commuting meets the requirements of everyday life much better than commuting on non-electrified bikes. The findings of this thesis suggest several pathways to strengthening this novel practice. The capacity of e-biking to serve mundane trips can for example be supported through the normalization of the use of weather- and transport relevant materials and competences. Deeper linkages with interacting practices from other sectors, such as an integration of cycling materials (GPS-trackers) into policing practices, can also con-tribute to this goal. With regard to research, the present work offers starting points for quantifications, for example on the relative importance of single elements as well as on the characteristics of their relations among each other or with regard to typical constellations of elements.

Description: The recently finalized research project "ZRR for municipal waste" aimed at testing and evaluating the automation of municipal waste sorting plants by supplementing or replacing manual sorting, with sorting by a robot with artificial intelligence (ZRR). The objectives were to increase the current recycling rates and the purity of the recovered materials; to collect additional materials from the current rejected flows; and to improve the working conditions of the workers, who could then concentrate on, among other things, the maintenance of the robots. Based on the empirical results of the project, this paper presents the main results of the training and operation of the robotic sorting system based on artificial intelligence, which, to our knowledge, is the first attempt at an application for the separation of bulky municipal solid waste (MSW) and an installation in a full-scale waste treatment plant. The key questions for the research project included (a) the design of test protocols to assess the quality of the sorting process and (b) the evaluation of the performance quality in the first six months of the training of the underlying artificial intelligence and its database.

Description: Cities are becoming digital and are aiming to be sustainable. How they are combining the two is not always apparent from the outside. What we need is a look from inside. In recent years, cities have increasingly called themselves Smart City. This can mean different things, but generally includes a look towards new digital technologies and claim that a Smart City has various advantages for its citizens, roughly in line with the demands of sustainable development. A city can be seen as smart in a narrow sense, technology wise, sustainable or smart and sustainable. Current city rankings, which often evaluate and classify cities in terms of the target dimensions 2smart" and "sustainable", certify that some cities are both. In its most established academic definitions, the Smart City also serves both to improve the quality of life of its citizens and to promote sustainable development. Some cities have obviously managed to combine the two. The question that arises is as follows: What are the underlying processes towards a sustainable Smart City and are cities really using smart tools to make themselves sustainable in the sense of the 2015 United Nations Sustainability Goal 11? This question is to be answered by a method that has not yet been applied in research on cities and smart cities: the innovation biography. Based on evolutionary economics, the innovation biography approaches the process towards a Smart City as an innovation process. It will highlight which actors are involved, how knowledge is shared among them, what form citizen participation processes take and whether the use of digital and smart services within a Smart City leads to a more sustainable city. Such a process-oriented method should show, among other things, to what extent and when sustainability-relevant motives play a role and which actors and citizens are involved in the process at all.

Description: The demand for metals from the entire periodic table is currently increasing due to the ongoing digitalization. However, their use within electrical and electronic equipment (EEE) poses problems as they cannot be recovered sufficiently in the end-of-life (EoL) phase. In this paper, we address the unleashed dissipation of metals caused by the design of EEE for which no globally established recycling technology exists. We describe the European Union's (EU) plan to strive for a circular economy (CE) as a political response to tackle this challenge. However, there is a lack of feedback from a design perspective. It is still unknown what the implications for products would be if politics were to take the path of a CE at the level of metals. To provide clarification in this respect, a case study for indium is presented and linked to its corresponding recycling-metallurgy of zinc and lead. As a result, a first material-specific rule on the design of so-called "anti-dissipative" products is derived, which actually supports designing EEE with recycling in mind and represents an already achieved CE on the material level. In addition, the design of electrotechnical standardization is being introduced. As a promising tool, it addresses the multi-dimensional problems of recovering metals from urban ores and assists in the challenge of enhancing recycling rates. Extending the focus to other recycling-metallurgy besides zinc and lead in further research would enable the scope for material-specific rules to be widened.

Description: Managing energy use by municipalities should be an important part of local energy and climate policy. The ISO 50001 standard constitutes an internationally recognized catalogue of requirements for systematic energy management. Currently, this standard is mostly implemented by companies. Our study presents an approach where consultants supported 28 European municipalities in establishing energy management systems. A majority (71%) of these municipalities had achieved ISO 50001 certification by the end of our study. We also conducted two surveys to learn more about motivations and challenges when it comes to establishing municipal energy management systems. We found that organizational challenges and resource constraints were the most important topics in this regard. Based on the experiences in our study we present lessons learned regarding supporting municipalities in establishing energy management systems.

Description: Supply risks and environmental concerns drive the interest in critical raw material recycling in the European Union. Globally, waste electrical and electronic equipment (WEEE) is projected to increase by almost 40% until 2030. This waste stream can be a source of secondary raw materials. The determination of the economic feasibility of recycling and recovering specific materials is a data-intensive, time-consuming, and case-specific task. This study introduced a two-part evaluation scheme consisting of upper continental crust concentrations and raw material prices as a simple tool to indicate the potential and limitations of critical raw material recycling. It was applied to the case of light-emitting diodes (LED) lamps in the EU. A material flow analysis was conducted, and the projected waste amounts were analyzed using the new scheme. Indium, gallium, and the rare earth elements appeared in low concentrations and low absolute masses and showed only a small revenue potential. Precious metals represented the largest revenue share. Future research should confirm the validity and usefulness of the evaluation scheme.

Description: The transformation of society into sustainable structures is one of the most important tasks for the future. That cities have a decisive role to play in this transformation process has been known at least since Rio 1992. They have enormous pressure to act for change: They are at the same time problem and solution for sustainable development. Currently there is another significant development for cities - the need and external pressure to be "smart", often understood merely as applying the latest digital technologies to become more efficient. The Smart City and the Sustainable City can work hand in hand or hinder each other, depending on their interpretation. In this study we focus on five Smart Cities in Western Germany to get a closer look at how they shape their processes and whether the underlying motivation is to become a technologically Smart City, focus on sustainable development, or both. With the help of the innovation biography research method, we show how cities shape the dynamic process towards forming a Smart City, the role sustainable urban development plays in the process, who the actors involved are, and the important role improved knowledge management then plays for the diffusion of the Smart Sustainable City within the region. It becomes clear how important communication and narratives are both in the process within each City towards forming a Smart Sustainable City and for the first step of diffusion, the adaptation of other cities within the region. This study is intended to serve both as a basis for cross-regional consideration and dialogue for the transfer of successful processes.

Description: Many cities all over the world highlight the need to transform their urban mobility systems into more sustainable ones, to confront pressing issues such as air and noise pollution, and to deliver on climate change mitigation action. While the support of innovations is high on the agenda of both national and local authorities, consciously phasing-out unsustainable technologies and practices is often neglected. However, this other side of the policy coin, "exnovation", is a crucial element for the mobility transition. We developed a framework to facilitate a more comprehensive assessment of urban mobility transition policies, systematically integrating exnovation policies. It links exnovation functions as identified in transition studies with insights from urban mobility studies and empirical findings from eight city case studies around the world. The findings suggest that most cities use some kinds of exnovation policies to address selective urban mobility issues, e.g., phasing-out diesel buses, restricting the use of polluting motor vehicles in some parts of the city, etc. Still, we found no evidence for a systematic exnovation approach alongside the innovation policies. Our framework specifies exnovation functions for the urban mobility transition by lining out policy levers and concrete measure examples. We hope that the framework inspires future in-depth research, but also political action to advance the urban mobility transition.

Description: Food and nutrition systems are linked to all Sustainable Development Goals (SDGs), which makes their transition toward social-ecological behavior patterns crucial for an overarching sustainability transformation. The perspective of (urban) logistics is of special interest. It couples the production and consumption physically and virtually. In this context, we shed light on the design of the turnover point of food in urban areas from the supply chain toward consumers and contribute to an overarching systemic perspective toward establishing a sustainable multilevel food system. We describe current patterns in urban food systems and propose several principles for sustainable design of (urban) food systems based on concepts such as (regional) collaboration and food literacy. Using these principles, we provide four design scenarios that concretely imagine future urban food consumption and production patterns titled "slow stock supply service," "deliver into the daily walk," "central district food depot," "super food action place." With this work we provide a starting for reflecting whether certain combinations of principles actually lead to patterns of daily life that are feasible, acceptable, or desirable. Moreover, we provide an initial qualitative assessment to stimulate further research that explores scenario pathways and incorporates additional indicators regarding the impact on social-ecological. We open up various research questions with regard to the overarching question of how urban food logistics should be designed to be consistent with the SDGs.

Description: Green hydrogen will play a key role in building a climate-neutral energy-intensive industry, as key technologies for defossilising the production of steel and basic chemicals depend on it. Thus, policy-making needs to support the creation of a market for green hydrogen and its use in industry. However, it is unclear how appropriate policies should be designed, and a number of challenges need to be addressed. Based on an analysis of the ongoing German debate on hydrogen policies, this paper analyses how policy-making for green hydrogen development may support industry defossilisation. For the assessment of policy instruments, a simplified multi-criteria analysis (MCA) is used with an innovative approach that derives criteria from specific challenges. Four challenges and seven relevant policy instruments are identified. The results of the MCA reveal the potential of each of the selected instruments to address the challenges. The paper furthermore outlines how instruments might be combined in a policy package that supports industry defossilisation, creates synergies and avoids trade-offs. The paper's impact may reach beyond the German case, as the challenges are not specific to the country. The results are relevant for policy-makers in other countries with energy-intensive industries aiming to set the course towards a hydrogen future.

Description: The Digital Product Passport (DPP) is a concept of a policy instrument particularly pushed by policy circles to contribute to a circular economy. The preliminary design of the DPP is supposed to have product-related information compiled mainly by manufactures and, thus, to provide the basis for more circular products. Given the lack of scientific debate on the DPP, this study seeks to work out design options of the DPP and how these options might benefit stakeholders in a product's value chain. In so doing, we introduce the concept of the DPP and, then, describe the existing regime of regulated and voluntary product information tools focusing on the role of stakeholders. These initial results are reflected in an actor-centered analysis on potential advantages gained through the DPP. Data is generated through desk research and a stakeholder workshop. In particular, by having explored the role the DPP for different actors, we find substantial demand for further research on a variety of issues, for instance, on how to reduce red tape and increase incentives for manufacturers to deliver certain information and on how or through what data collection tool (e.g., database) relevant data can be compiled and how such data is provided to which stakeholder group. We call upon other researchers to close the research gaps explored in this paper also to provide better policy direction on the DPP.

Description: To limit global warming, the use of carbon capture and storage technologies (CCS) is considered to be of major importance. In addition to the technical-economic, ecological and political aspects, the question of social acceptance is a decisive factor for the implementation of such low-carbon technologies. This study is the first literature review addressing the acceptance of industrial CCS (iCCS). In contrast to electricity generation, the technical options for large-scale reduction of CO2 emissions in the energy-intensive industry sector are not sufficient to achieve the targeted GHG neutrality in the industrial sector without the use of CCS. Therefore, it will be crucial to determine which factors influence the acceptance of iCCS and how these findings can be used for policy and industry decision-making processes. The results show that there has been limited research on the acceptance of iCCS. In addition, the study highlights some important differences between the acceptance of iCCS and CCS. Due to the technical diversity of future iCCS applications, future acceptance research must be able to better address the complexity of the research subject.

Description: Schools play an important role in achieving climate protection goals, because they lay the foundation of knowledge for a responsible next generation. Therefore, schools as institutions have a special role model function. Enabling schools to become aware of their own carbon footprint (CF) is an important prerequisite for being able to tap the substantial CO2 reduction potential. Aiming at the direct involvement of students in the assessment process, a new assessment tool was developed within the Schools4Future project that gives students the opportunity to determine their own school's CF. With this instrument the CO2 emissions caused by mobility, heating and electricity consumption as well as for food in the school canteen and for consumables (paper) can be recorded. It also takes into account existing renewable energy sources. Through the development of the tool, not only a monitoring instrument was established but also a concrete starting point from which students could take actions to reduce Greenhouse Gas (GHG) emissions. This paper presents the tool and its methods used to calculate the CF and compares it with existing approaches. A comparative case study of four pilot schools in Germany demonstrates the practicability of the tool and reveals fundamental differences between the GHG emissions.

Description: More than 150 municipal utilities (so-called Stadtwerke) were established in Germany from the beginning of the millennium, bringing the total number of Stadtwerke currently established within the country to approximately 900. With responsibility for more than half of the supply of electricity, gas and heat in Germany, these Stadtwerke play a central role in the transformation of the energy sector, or Energiewende. In addition, due to their local and regional ties, Stadtwerke have a particular role to play in energy politics, the economy and across society. This article focuses on the motives behind, and grounds for, the current wave of newly established Stadtwerke. Further, it discusses the factors that were critical to the successful formation of new Stadtwerke in recent years. The results of our survey indicate that the establishment of municipal Stadtwerke is a suitable measure to implement the energy transition at the local level, whereby the concept of public value has a high level of importance for the local decision-makers. Collaboration and cooperation, as well as a resilience-oriented strategy, are important success factors for new Stadtwerke.

Description: The need for a transition towards a circular economy (CE) is evident, as the current economic model is based on the exploitation of far more resources than the planet can replenish sustainably. A significant part of this economic transition is the inception of new, CE-oriented startups and business activities. While business model frameworks (BMF), such as the Business Model Canvas (BMC), were at the center of discussions about structuring business ideas in the beginning of the millennium, the conversation must now shift towards circular BMFs (CBMF). This paper follows the Design Research Methodology (DRM) for an empirical approach to devising a novel CBMF, including expert interviews as well as a first application of the framework with a startup. Throughout this process, a new and innovative tool called Circular Business Framework (CBF) was created and tested based on CE principles.

Description: Transponder-based Aircraft Detection Lighting Systems (ADLS) are increasingly used in wind turbines to limit beacon operation times, reduce light emissions, and increase wind energy acceptance. The systems use digital technologies such as receivers of digital transponder signals, LTE/5G, and other information and communication technology. The use of ADLS will be mandatory in Germany both for new and existing wind turbines with a height of 〉100 m from 2023 (onshore) and 2024 (offshore), so a nationwide rollout is expected to start during 2022. To fully realize the benefits while avoiding risks and bottlenecks, a thorough and holistic understanding of the efforts required and the impacts caused along the life cycle of an ADLS is essential. Therefore, this study presents the first multi-aspect holistic evaluation of an ADLS. A framework for evaluating digital applications in the energy sector, previously developed by the authors, is refined and applied. The framework is based on multi-criteria analysis (MCA), life cycle assessment (LCA), and expert interviews. On an aggregated level, the MCA results show an overall positive impact from all stakeholders’ perspectives. Most positive impacts are found in the society and politics category, while most negative impacts are of technical nature. The LCA of the ADLS reveals a slightly negative impact, but this impact is negligible when compared to the total life cycle impact of the wind turbines of which the ADLS is a part. Besides the aggregated evaluation, detailed information on potential implementation risks, bottlenecks, and levers for life cycle improvement are presented. In particular, the worldwide scarcity of the required semiconductors, in combination with the general lack of technicians in Germany, lead to the authors’ recommendation for a limited prolongation of the planned rollout period. This period should be used by decision-makers to ensure the availability of technical components and installation capacities. A pooling of ADLS installations in larger regions could improve plannability for manufacturers and installers. Furthermore, an ADLS implementation in other countries could be supported by an early holistic evaluation using the presented framework.

Description: The study investigates if causal claims based on a theory-of-change approach for impact reporting are credible. The authors use their most recent impact report for a Social Bond to show how theory-based logic models can be used to map the sustainability claims of issuers to quantifiable indicators. A single project family (homeownership loans) is then used as a case study to test the underlying hypotheses of the sustainability claims. By applying Bayes Theorem, evidence for and against the claims is weighted to calculate the degree to which the belief in the claims is warranted. The authors found that only one out of three claims describe a probable cause–effect chain for social benefits from the loans. The other two claims either require more primary data to be corroborated or should be re-defined to link the intervention more closely and robustly with the overarching societal goals. However, all previous reported indicators are below the thresholds of the most conservative estimates for fractions of beneficiaries in the paper at hand. We conclude that the combination of a Theory-of-Change with a Bayesian Analysis is an effective way to test the plausibility of sustainability claims and to mitigate biases. Nevertheless, the method is - in the presented form - also too elaborate and time-consuming for impact reporting in the sustainable finance market.

Description: The development of digital technologies is accelerating, enabling increasingly profound changes in increasingly short time periods. The changes affect almost all areas of the economy as well as society. The energy sector has already seen some effects of digitalization, but more drastic changes are expected in the next decades. Besides the very positive impacts on costs, system stability, and environmental effects, potential obstacles and risks need to be addressed to ensure that advantages can be exploited while adverse effects are avoided. A good understanding of available and future digital applications from different stakeholders' perspectives is necessary. This study proposes a framework for the holistic evaluation of digital applications in the energy sector. The framework consists of a combination of well-established methods, namely the multi-criteria analysis (MCA), the life cycle assessment (LCA), and expert interviews. The objective is to create transparency on benefits, obstacles, and risks as a basis for societal and political discussions and to supply the necessary information for the sustainable development and implementation of digital applications. The novelty of the proposed framework is the specific combination of the three methods and its setup to enable sound applicability to the wide variety of digital applications in the energy sector. The framework is tested subsequently on the example of the German smart meter roll-out. The results reveal that, on the one hand, the smart meter roll-out clearly offers the potential to increase the system stability and decrease the carbon emission intensity of the energy system. Therefore, the overall evaluation from an environmental perspective is positive. However, on the other hand, close attention needs to be paid to the required implementation and operational effort, the IT (information technology) and data security, the added value for the user, the social acceptance, and the realization of energy savings. Therefore, the energy utility perspective in particular results in an overall negative evaluation. Several areas with a need for action are identified. Overall, the proposed framework proves to be suitable for the holistic evaluation of this digital application.

Description: In the energy sector, few topics, if any, are more hyped than hydrogen. Countries develop hydrogen strategies to provide a perspective for hydrogen production and use in order to meet climate-neutrality goals. However, in this topical field the role of water is less accentuated. Hence, in this study, we seek to map the interrelations between the water and wastewater sector on the one hand and the hydrogen sector on the other hand, before reflecting upon our findings in a country case study. We chose the Hashemite Kingdom of Jordan because (i) hydrogen is politically discussed not least due to its high potentials for solar PV, and (ii) Jordan is water stressed - definitely a bad precondition for water-splitting electrolyzers. This research is based on a project called the German-Jordanian Water-Hydrogen-Dialogue (GJWHD), which started with comprehensive desk research mostly to map the intersectoral relations and to scope the situation in Jordan. Then, we carried out two expert workshops in Wuppertal, Germany, and Amman, Jordan, in order to further discuss the nexus by inviting a diverse set of stakeholders. The mapping exercise shows various options for hydrogen production and opportunities for planning hydrogen projects in water-scarce contexts such as Jordan.

Description: The Digital Product Passport (DPP) is a concept for collecting and sharing product-related information along the life cycle of a product. DPPs are currently the subject of intense discussion, and various development efforts are being undertaken. These are supported by regulatory activities, especially in the case of the battery passport. The aggregation of product life-cycle data and their respective use, as well as the sharing of these data between companies, entrepreneurs, and other actors in the value chain, is crucial for the creation of a resource-efficient circular economy. Despite the urgent need for such a solution, there is currently little attention given to the digital infrastructure for the creation and handling of the DPPs (i.e., the so-called DPP system). Moreover, there is so far no common understanding of what the requirements for a DPP system are. This is the background and underlying motivation of our paper: we identify the requirements for a DPP system in a structured way, i.e., based on stakeholder involvement and current literature from science and industry. In addition, we compose, categorize, and critically analyze the results, i.e., the list of requirements for DPP systems, in order to identify gaps. Summarized, our research provides insights into the criteria to be considered in the creation of an actual DPP system.

Description: The food system plays a crucial role in mitigating climate change. Even if fossil fuel emissions are halted immediately, current trends in global food systems may prevent the achieving of the Paris Agreement's climate targets. The high degree of variability and uncertainty involved in calculating diet-related greenhouse gas emissions limits the ability to evaluate reduction potentials to remain below a global warming of 1.5 or 2 degrees. This study assessed Western European dietary patterns while accounting for uncertainty and variability. An extensive literature review provided value ranges for climate impacts of animal-based foods to conduct an uncertainty analysis via Monte Carlo simulation. The resulting carbon footprints were assessed against food system-specific greenhouse gas emission thresholds. The range and absolute value of a diet carbon footprint become larger the higher the amount of products with highly varying emission values in the diet. All dietary pattern carbon footprints overshoot the 1.5 degrees threshold. The vegan, vegetarian, and diet with low animal-based food intake were predominantly below the 2 degrees threshold. Omnivorous diets with more animal-based product content trespassed them. Reducing animal-based foods is a powerful strategy to decrease emissions. However, further mitigation strategies are required to achieve climate goals.

Description: To date, the circular economy has fallen short of its promise to reduce our resource demand and transform our production and consumption system. One key problem is the lack of understanding that highly promising strategies such as refuse, rethink, and reduce can be properly addressed using research on sufficiency. This article argues that a shift in focus is required in research and policy development from consumers who buy and handle circularly designed products to consumption patterns that follow the logic of sufficiency and explain how sufficiency-oriented concepts can be incorporated into existing social practices. The authors show that sufficiency is not necessarily as radical and unattractive as is often claimed, making it a suitable yet underrated strategy for sustainability and the transition to an effective circular economy. The case of urban gardening shows that small interventions can have far-reaching effects and transform consumption patterns as the logic of availability is contested by newly developed concepts of "enoughness" and opposition to "über-availability." The authors propose utilizing comprehensive state-of-the-art theories of consumption and human action when developing strategies and policies to make the circular economy sustainable while being more critical of utilitarian approaches. Using social practice theories that have proven to be beneficial allows human actions to be comprehensively analyzed by recognizing their embeddedness in social and material frameworks; addressing the meaning, competences, and materials of routinized human behavior; and examining indirect effects.

Description: The number of motorcycle taxis has soared in East African cities over the last decades, filling a gap in mobility needs while providing revenue opportunities to drivers. However, poor road safety combined with contribution to carbon emissions and air pollution creates a sustainability conundrum, which has led governments to control or repress the mode, yet without much success. After reviewing the characteristics and regulation of motorcycle taxis in Nairobi, Kigali, and Kampala, this study investigates the existence and impacts of two recent trends: digitalization and electrification. A comprehensive approach is adopted with a systematic review of the literature and policies, completed by field research and key informant interviews. We find out that electrification is mostly associated with positive impacts covering a spectrum of environment, economics, health, and social-related benefits, while the benefits of digitalization are more uncertain or contested. Impacts are however limited for both at the time of study as digitalization is highly volatile and electrification nascent. In conclusion, the paper identifies an interlinkage between the trends via the example of data, and further key research needs.

Description: In view of the accelerating climate crisis, the Russian invasion of Ukraine highlighted the dependency of fossil fuels on the part of Germany and the European Union (EU). With the priority aim to reduce the import dependency from the Russian Federation while providing energy security and staying on track with climate mitigation efforts, the Federal Government was presented with major challenges. Prior to the war, an approximate 34% of the mineral oil, 53.6% of the natural gas, and 50% of hard coal supplies to Germany originated from Russian sources. As of 2023, however, Germany is independent from Russian energy imports. This paper examines implications of the global energy crisis induced by the invasion on the energy sector in Germany. As a basis for achieving this analysis, a short overview of the energy situation in the country before the war and a demonstration of the provisional conditions is presented. This is followed by an analysis of the main consequences of the war and medium and long-term strategies to reach Germany's climate goals while maintaining energy security. Lastly, foreseeable consequences regarding the European and German climate goals are discussed.

Description: The transport sector accounts for 20 per cent of the greenhouse gas emissions in Germany and it is therefore key to success for German climate policy. At present, however, there is no other sector with a wider gap in missing the trajectory to climate neutrality. The present study, conducted on behalf of Huawei within the project "Shaping the Digital Transformation - Digital Solution Systems for the Sustainability Transition", points out new pathways towards a sustainable and climate friendly transition of the transport sector. The report specifies concrete options to follow up on the ambitious goals of the new coalition agreement to foster clean and digital mobility solutions. The authors refined eight theses on how digitalisation can foster sustainable mobility solutions and how to shape a supporting policy framework, which is aligning the financial and regulatory guardrails for ramping up a sustainable mobility system while gradually phasing down the usage of private cars.

Description: The current, private car-based mobility system is not sustainable: it contributes to climate change, it is unjust from gender- and socio-economic perspectives, endangers health and obstructs urban space. To counteract this, mobility data offers entirely new avenues for planning, organizing, and implementing mobility and transport. This strategy paper considers two possible ways to use mobility data for improving environmental sustainability and equitable access to transportation in Germany.

Description: The word "literacy" has come to be used to describe a wide range of competencies, including design literacy - a term that, despite its presence in design discourse, is still characterised by a certain fuzziness. In this paper, we explore this highly discursive theoretical field in order to gain a more nuanced and expanded understanding of the topic. In doing so, we argue that these divergent positions are also due to the ambiguity of the term “design”. We understand design as the perpetual de- and reconstruction of the world, as a way of worldmaking, both physically and conceptually. Thus, design literacy can be understood as a way to perceive traces of design and its processes, to perceive the world as contingent: a circular cognitive process of recognising that something - if not everything - in our cultural pluriverse is designed, understanding how it was designed and that it can potentially become the subject of design again and again. In our paper, we emphasise the contingency of design - and the ethical level that can arise from understanding the possibility of a different design. Ultimately, our aim with this paper is to emphasise that design literacy is a crucial competence for encouraging pluralistic perspectives and initiating transition processes, as it helps to acknowledge the temporary necessity but long-term non-necessity of things (which particularly includes the transitory nature of one's own creations).

Description: 22 years are left until the German target for climate neutrality should be reached. For the industrial sector, this implies a fundamental change and an acceleration of emission reduction, as from 2000 to 2021 the sector has reduced its greenhouse gas (GHG) emissions by only 13% (ERK, 2022). For the large structures, plants and assets that are characteristic for the energy intensive industrial sectors, the timespan implies no room for delay. One sector facing particular challenges is the chemical industry. Here, fossil resources are used not only for energetic purposes but for feedstock as well, in the petrochemical industry in particular. The efforts made in the petrochemical sector thereby not only affects the sectors own emissions, but the chemicals value chain at large, including the management of end-of-life products. The dependency on energetic resources for material use also means that there is a particular connection from the chemical industry to the energy system at large, which also entails special consideration. The chemical industry also has a particular relevance to the Antwerp-Rotterdam-Rhine-Ruhr-Area (ARRRA) which hosts several large petrochemical clusters in Germany as well as the Netherlands and Belgium, with complexly interlinked production chains. In reaching the climate targets, these regions especially face significant changes and may have the opportunity to position themselves as frontrunners for industrial transformation. That is, if a successful strategy can be found. In the recent years, numerous scenario analyses and roadmaps have been released drawing out pathways for chemical industries to develop in line with national and international climate targets. This can entail mapping of technological options, important prerequisites, particular challenges as well as important opportunities and timeframes. This meta-analysis summarizes and compares the findings of some of the most recent previous works at the national, European and global level. As the goal is to investigate the various strategic options and development paths for Germany and the ARRRA, it has a particular focus on roadmaps for Germany, the Netherlands and Belgium. It takes a quantitative as well as qualitative approach, looking both at resource and production volumes, different emission reduction strategies relative importance, as well as policy recommendations and other important framework conditions. A particular focus is put on the use of non-fossil feedstocks to reduce emissions.

Description: Community-based approaches to natural resource management are being discussed and experienced as promising ways for pursuing ecological conservation and socio-economic development simultaneously. However, the multiplicity of levels, scales, objectives and actors that are involved in sustainability transformations tends to be challenging for such bottom-up approaches. Collaborative and polycentric governance schemes are proposed for dealing with those challenges. What has not been fully explored is how knowledge from local contexts of community-based initiatives can be diffused to influence practices on higher levels and/or in other local contexts. This study explores how theoretical advances in the diffusion of grassroots innovation can contribute to understanding and supporting the diffusion of knowledge and practices from community-based initiatives and proposes a transdisciplinary approach to diffusion. For that aim, we develop an analytical perspective on the diffusion of grassroots innovations that takes into consideration the multiplicity of actors, levels and scales, the different qualities/types of knowledge and practices, as well as their respective contributions. We focus on the multiplicity and situatedness of cognitive frames and conceptualize the diffusion of grassroots innovations as a transdisciplinary process. In this way three different diffusion pathways are derived in which the knowledge and practices of grassroots initiatives can be processed in order to promote their (re)interpretation and (re)application in situations and by actors that do not share the cognitive frame and the local context of the originating grassroots initiative. The application of the developed approach is illustrated through transdisciplinary research for the diffusion of sustainable family farming innovations in Colombia. This conceptualization accounts for the emergence of multiplicity as an outcome of diffusion by emphasizing difference as a core resource in building sustainable futures.

Description: Public catering has become increasingly important in recent years. With increasing annual customers, the sector's impact on the environment is also growing continuously. At the same time, public catering offers a lever to promote sustainable nutrition that has rarely been used so far. Small changes in kitchen practices and food offers can thus be multiplied into a significant positive impact on environmental challenges, such as climate change or loss of biodiversity due to the large number of servings. In contrast to private households, management decisions in public catering can influence the food-related environmental impact of thousands of customers. This article deals with the nationwide level of greenhouse gas (GHG) emissions and resource use in the German public catering segment "business" and its saving potentials by different scenarios of unsupported and supported recipe revision. In this paper, we define "unsupported" as the intuitive optimization of recipes by employees of public catering businesses. In contrast, "supported" approaches had to meet specific target goals, for example of the Deutsche Gesellschaft für Ernährung; engl. German Nutrition Society or the sustainable level. Specifically, we will test how (A) an unsupported recipe revision, (B) a recipe revision based on dietary recommendations and (C) a recipe revision using scientific guidance affect the environmental impact of a dish. As a methodological framework, an online survey of public catering companies was conducted as well as a scenario analysis at menu level and at nationwide level. The results are based on empirical data on the one hand, and on extrapolations on the other. The results show that the nationwide implementation of recipe revision according to scientific guidance-such as concrete target goals for the GHG emissions per serving-can save up to 44% of resource use in the German business catering sector (which corresponds to 3.4 million tons of resources per year) and as much as 40% of GHG emissions (0.6 million tons GHG emissions per year). Even in the scenario of unsupported recipe revision, GHG and resource savings of up to 20% can be realized. The results show that public catering can reduce its material and carbon footprint by 20% overnight. Moreover, the findings show indications for the sustainable transformation of public catering. Nevertheless, it must be noted that these are some first steps of the transformation, which will require further changes with even greater impacts and political activities.

Description: Sufficiency measures are potentially decisive for the decarbonisation of energy systems but rarely considered in energy policy and modelling. Just as efficiency and renewable energies, the diffusion of demand-side solutions to climate change also relies on policy-making. Our extensive literature review of European and national sufficiency policies fills a gap in existing databases. We present almost 300 policy instruments clustered into relevant categories and publish them as "Energy Sufficiency Policy Database". This paper provides a description of the data clustering, the set-up of the database and an analysis of the policy instruments. A key insight is that sufficiency policy includes much more than bans of products or information tools leaving the responsibility to individuals. It is a comprehensive instrument mix of all policy types, not only enabling sufficiency action, but also reducing currently existing barriers. A policy database can serve as a good starting point for policy recommendations and modelling, further research is needed on barriers and demand-reduction potentials of sufficiency policy instruments.

Description: Nigeria is Africa's top cement producer and could be on course to be one of the top producers globally. The goal of this study is to identify and critically examine the pathways available to Nigeria to meet its decarbonisation goals in the cement sector. Based on a literature review, the study assesses demand drivers and decarbonisation potentials for the sector. It then presents two different quantitative pathways for growth in production of cement by 2050, and three different pathways for decarbonisation of the sector. Using published data and a scenario analysis tool, the study calculates how the sector's emissions might evolve under each of these pathways. The results indicate that, in the most ambitious scenario, emissions from the sector can plateau by the late 2030s, resulting in an overall increase of 21% by 2050 (compared to 2015 levels). Achieving this scenario is necessary in order to put the sector on a path to net zero emissions beyond 2050. The scenario is driven by reductions in both energy-related and process emissions, as well as a small share of carbon capture and storage and demand management. A moderately ambitious scenario that relies mostly on savings on energy-related emissions results in an 84% increase in emissions by 2050. Finally, the Business-as-Usual scenario results in an almost tripling of emissions by 2050. The results indicate a strong potential for policies to drive improvements in energy efficiency and clinker-to-cement ratio. Critical areas of uncertainty within the assumptions include the production rates (including the evolution of the export market) and the fuel mix.

Description: The Glasgow climate conference marked a symbolic juncture, lying half-way between the adoption of the UNFCCC in 1992 and the year 2050 in which according to the IPCC special report on the 1.5°C limit net zero CO2 emissions need to be reached, globally, in order to maintain a good chance of achieving the 1.5°C limit. This article undertakes an assessment of what the UNFCCC and in particular the Paris Agreement and its implementation process have actually achieved so far up to and including the results of the Glasgow conference. The article discusses efforts at ambition raising both within and outside the formal diplomatic process, the finalization of the implementation rules of the Paris Agreement, as well as progress on gender responsiveness, climate finance, adaptation and loss and damage. In summary, the Paris Agreement and its implementation can be considered a success as it is having a discernible impact on the behavior of parties as well as on non-party actors. However, significant further efforts will be required to actually achieve the objectives of the Agreement.

Description: The circle is a ubiquitous metaphor in the current scientific and political debate on possible strategies for coping with the changes brought by the so-called "Anthropocene". Terms such as "recycling", "upcycling", "downcycling", "life cycle" or "circular economy" all refer to the same geometric shape, which in turn can be found in numerous diagrams illustrating the respective design approaches and political strategies. But how does the circle shape the way we think and act as designers? Is it an appropriate metaphor to guide us to feasible actions, or is its degree of simplification too far removed from reality? In this article we look at the circular economy as a designed model, and question the circle as a communication tool for the cultural project of sustainability. As the circle may carry the risk of an oversimplified, unattainable, even disillusioning ideal, we discuss various alternative images and forms for their potential to become metaphors of alternative models. The hole, the plate, the pasture, the wheel, the mill wheel, the hamster wheel, the vortex, the double helix, the spider web and the rhizome - as metaphors, they each open up different perspectives and approaches to reality, they each construct different relationships and dependencies between nature and culture. The aim of this article is less about postulating the end of the circle as a metaphor in the sustainability debate, as it is about to fathom the circle's ends as a metaphorical tool. In other words, when does the metaphor of the circle become too abstract? As designers we can say that falling in love with a form right at the beginning of a design process can be rather limiting, as hardly any alternatives will be considered, and all further decisions are subordinated to achieving the desired shape. Therefore, we would like to emphasise the contingency of the circular economy as a model. We would like to welcome the thought that the circle has an "end".

Description: Although smart energy technologies (SETs) can fulfill multiple tasks in increasingly decarbonized and digitalized energy systems, market diffusion is still limited. This study investigates which beliefs influence consumers' intention to adopt two smart-energy offerings, whether the rapid growth of the smart home market will now drive SET adoption, and if consumer-driven diffusion will lead to sustainability potentials being realized. Building on UTAUT2, a new theoretical model is proposed, and a consumer acceptance survey was conducted in Germany (n = 700). Results indicate that a growing smart home market will not increase SET adoption and that "adjustable green defaults" should be introduced.

Description: The EU Horizon 2020 project HiEff-BioPower (grant agreement No 727330, duration: 10/2016 - 09/2021) aimed at the development of a new, innovative, fuel flexible and highly efficient biomass CHP technology for a capacity range of 1 to 10 MW total energy output, suitable e.g. for on-site generation at larger residential apartment buildings or local heat grids. The new technology shall define a new milestone in terms of CHP efficiency and contribute to a sustainable energy supply based on renewable energies using otherwise unused residual biomass. It consists of a fuel-flexible updraft gasification technology with ultra-low particulate matter emissions, an integrated gas cleaning system and a solid oxide fuel cell (SOFC). The technology shall be applicable for a wide fuel spectrum for residual biomass (wood pellets, wood chips or selected agricultural fuels like agro-pellets) and achieve high gross electric (40%) and overall (90%) efficiencies as well as almost zero gaseous and particulate matter (PM) emissions (close or below the level of detection) as non-energy benefits. At the end of the project, final technology data has become available, as well as techno-economic analyses and market studies. Based on this data, this paper presents final results from the environmental impact assessment of the new HiEff-BioPower technology.

Description: In Argentina, renewable energies are promoted as a way of decarbonising the electricity mix and providing reliable energy services. The national goal is to generate 20% of electricity from renewable sources by 2025. However, despite significant natural potential, solar photovoltaic still represents only a small share of Argentina's total electricity generation. Although this picture may look bleak, a wide range of market segments relating to decentralised photovoltaic generation in Argentina have developed. The general objective of this study is to examine the dynamics that currently enable or constrain the diffusion of distributed photovoltaic systems in Argentina. By applying the Technical Innovation System (TIS) approach, the aim is to understand which functions of the system are strong/weak and how these are influenced by endogenous/exogenous system strengths and weaknesses. To that end, a mixed method research strategy is applied. The exploratory sequential research design allows first to explore system strengths and weaknesses based on qualitative approaches, and then to further analyse the contextual embeddedness and the level of importance of the identified variables using quantitative survey instruments. Thereby, this study provides an important analytical method that contributes to a more nuanced understanding of the interdependencies of the TIS. The empirical results indicate that system weaknesses are shaped to a large extent by the overall contextual dynamics - such as political instability, energy subsidies and high inflation rates. System strengths relate to both the TIS itself (particularly knowledge development through pilot projects and market formation through provincial and national support programmes), to contextual relationships (linked to the availability of educational institutions that enable the rapid diffusion of knowledge) and to the importance of rural areas as protected spaces for the application of photovoltaic systems. Consequently, the study highlights the challenges to overcome for the broader diffusion of distributed photovoltaic generation.

Description: The establishment of the Leveraging a Climate-neutral Society–strategic Research Network (LCS–RNet) (then named the International Research Network for Low Carbon Societies) was proposed at the Group of Eight (G8) Environment Ministers’ Meeting in 2008. Its 12th annual meeting in December 2021 focused on the discussion on how to transition into a just and sustainable society and how to reduce the risks associated with the transition. This requires comprehensive studies including on the concept of transition, pathways to net-zero societies and how to realise the pathways by collaborating with various stakeholders. This Special Feature provides new insights into sustainability science by linking the scientific knowledge with practical science for the transition through the exploration of studies presented at the annual meeting. Following the opening paper, "A challenge for sustainability science: can we halt climate change?", a wide range of topics were discussed, including practices for sustainable transformation in the Erasmus University, practices in industry, energy transition and international cooperation.

Description: This paper examines the current and prospective greenhouse gas (GHG) emissions of e-fuels produced via electrolysis and Fischer-Tropsch synthesis (FTS) for the years 2021, 2030, and 2050 for use in Germany. The GHG emissions are determined by a scenario approach as a combination of a literature-based top-down and bottom-up approach. Considered process steps are the provision of feedstocks, electrolysis (via solid oxide co-electrolysis; SOEC), synthesis (via Fischer-Tropsch synthesis; FTS), e-crude refining, eventual transport to, and use in Germany. The results indicate that the current GHG emissions for e-fuel production in the exemplary export countries Saudi Arabia and Chile are above those of conventional fuels. Scenarios for the production in Germany lead to current GHG emissions of 2.78-3.47 kgCO2-eq/L e-fuel in 2021 as the reference year and 0.064-0.082 kgCO2-eq/L e-fuel in 2050. With a share of 58-96%, according to the respective scenario, the electrolysis is the main determinant of the GHG emissions in the production process. The use of additional renewable energy during the production process in combination with direct air capture (DAC) are the main leverages to reduce GHG emissions.

Description: Direct air capture (DAC) combined with subsequent storage (DACCS) is discussed as one promising carbon dioxide removal option. The aim of this paper is to analyse and comparatively classify the resource consumption (land use, renewable energy and water) and costs of possible DAC implementation pathways for Germany. The paths are based on a selected, existing climate neutrality scenario that requires the removal of 20 Mt of carbon dioxide (CO2) per year by DACCS from 2045. The analysis focuses on the so-called "low-temperature" DAC process, which might be more advantageous for Germany than the "high-temperature" one. In four case studies, we examine potential sites in northern, central and southern Germany, thereby using the most suitable renewable energies for electricity and heat generation. We show that the deployment of DAC results in large-scale land use and high energy needs. The land use in the range of 167-353 km2 results mainly from the area required for renewable energy generation. The total electrical energy demand of 14.4 TWh per year, of which 46% is needed to operate heat pumps to supply the heat demand of the DAC process, corresponds to around 1.4% of Germany's envisaged electricity demand in 2045. 20 Mt of water are provided yearly, corresponding to 40% of the city of Cologne's water demand (1.1 million inhabitants). The capture of CO2 (DAC) incurs levelised costs of 125-138 EUR per tonne of CO2, whereby the provision of the required energy via photovoltaics in southern Germany represents the lowest value of the four case studies. This does not include the costs associated with balancing its volatility. Taking into account transporting the CO2 via pipeline to the port of Wilhelmshaven, followed by transporting and sequestering the CO2 in geological storage sites in the Norwegian North Sea (DACCS), the levelised costs increase to 161-176 EUR/tCO2. Due to the longer transport distances from southern and central Germany, a northern German site using wind turbines would be the most favourable.

Description: The adoption of the Paris Agreement in 2015 and the passing of the Climate Action Law in Germany in 2019 established the legal need for the basic material industry in Germany to decarbonise. For the industry sector, the target is sets at a 49-51% GHG reduction by 2030 compared to 1990. Even though the sector specific targets are likely to become obsolete, a Hydrogen Strategy, Industry Strategy and Climate Protection Contracts are currently being developed or elaborated on. These are to further ensure and enable the basic material industry in Germany to decarbonise. These developments are emphasising the relevance of studying the industry decarbonisation at the time of conducting this research. As the institutionalisation of the industry decarbonisation is influenced by discourse, the analysis of the discourse is an important tool for studying the power effects produced by and built into the discourse. This is the first research aiming to provide a structured analysis of the discourse on industry decarbonisation in Germany. Drawing on discourse analysis and the Multilevel-Perspectives framework, this research investigated the power and dominance of storylines to influence the discourse of the industry transformation towards decarbonisation. In this research insights were obtained into the storylines used in this discourse, the actors who are part of this discourse, the frequency of storylines used and the percentage of actors making use of these storylines. Additionally, insights were generated into the discursive network and potential coalitions. This research made use of the Discourse Network Analysis software in combination with Visone and Excel for data collection, analysis, and visualisation. Based on 117 documents of various categories from the years 2012 to 2023, the discourse on German industry decarbonisation is discovered to be dominated by storylines of mainly technological or economic nature. The general sentiment discovered by the different actors is positive with the storylines focusing on establishing the conditions for the industry to decarbonise and no resistance being communicated. The discourse is furthermore dominated by most storylines. 18 out of 27 storylines are being used by more than 56% of all actors. The high overlap in storyline indicates discursive homogeneity. The homogeneity is further indicated through the lack of emerging discourse coalitions and the therewith connected lack of struggles for discursive dominance. One coalition can be defined with some actors being deeper involved and some being less involved in the discourse. As decisions on the transition path for Germany's industry to decarbonise are still to be taken the lack of discursive struggles has come to my surprise. In the discussion I reflect on how the positive sentiment, the discursive homogeneity and the great number of dominant storylines may come about.

Description: The original objectives for introducing Energy Performance Certificates (EPCs) were 1) to make energy performance transparent in the building market, as a measure of energy costs of using a building that a potential buyer or tenant would be interested in; and 2) to encourage energy efficiency renovation. However, the current implementation of EPC schemes in the Member States still shows significant challenges in achieving these two objectives. The recast of the EU Directive on the Overall Energy Performance of Buildings (EPBD) provides a chance to enhance both the usefulness and quality of EPCs and the EPC schemes overall. This document aims to inform both the debate on the recast of the EPBD and the enhancement of national EPC schemes in EU Member States. It presents the draft policy recommendations of the Horizon 2020 QualDeEPC project for making the EPBD and the national schemes more effective, particularly for deep renovation, and enhance their quality overall. The policy recommendations particularly target the link between EPCs and deep (energy) renovation1, while increasing the levels of ambition and convergence across the EU in terms of building renovation. Deep (energy) renovation is crucial for mitigating climate change and for energy security. The EPBD and all of its articles, as well as national EPC schemes, should aim to make deep (energy) renovation the default. This objective would be embedded and ensured in EPC schemes, if the policy recommendations provided in this document were adopted and implemented.

Description: At the next United Nations (UN) climate conference in the United Arab Emirates at the end of 2023, the first Global Stocktake (GST) of the Paris Agreement is due to conclude. The main goal of this process is to feed into a new round of Nationally Determined Contributions (NDCs) by Parties to the Agreement for 2035. In addition, the GST is aimed at identifying opportunities for strengthening international cooperation to achieve the Paris goals. The GST represents the first opportunity for Parties and other stakeholders to collectively highlight opportunities for international climate cooperation. Specifically, outcomes should plant the seeds for the development of concrete sectoral decarbonization roadmaps that could guide international cooperation in years to come.

Description: This Wuppertal Paper analyses the energy transition models of Colombia and Germany. The emphasis of the exercise is on an analysis of options for the complete decarbonization of the energy system in Colombia as a Global South country. To this end, it analyses the current situation, projections, public policy and narratives, and contrasts it with Germany as one of the countries of the Global North with which Colombia has historically maintained energy trade relations and is currently collaborating in the exploration of energy alternatives for decarbonization. Detailed analysis of sectoral energy consumption in Colombia shows the sectors with the highest fossil energy consumption (in this order): transport (fuels), industry (gas, coal), electricity generation (gas, coal) and residential (gas). We show the projected increase in demand for fuels and electricity, and calculate the amount of electricity theoretically needed to substitute fossil sources in each sector. We estimate the total electricity required for decarbonization via sector coupling and derive a first estimation of the range of additional renewable energy capacities needed to supply this demand. We find that required capacities are expectedly large (56-110 GW), depending on decarbonization pathways, and that export capacity beyond national demand may be limited. Our analysis of the policy and scenario arena in both countries finds that Colombia is still lacking both sector-specific decarbonization strategies and an embedding in a systemic vision of a systemic energy transition. Germany has more advanced sector strategies and (national) systemic visions, but lacks embedding assumptions on energy imports in a global-system analysis, i.e. in the analysis of an energy transition in potential exporting countries like Colombia. We formulate requirements to close these gaps in our conclusions.

Description: Rising energy costs have led to increased discussion about the social impact of the energy transition in Germany in recent years. In 2021, a gradually increasing CO2 tax was introduced. This paper analyzes the question of whether a CO2 tax can be socially just. Using data analysis and desk research, correlations between income and energy consumption in Germany are shown. In a short analysis, it is investigated which additional burdens different types of private households have to expect in the coming years due to the introduction of CO2 pricing on energy. In particular, the introduction of a per capita flat rate fed by CO2 tax revenues could be a suitable way to reduce the burden on low-income households.

Description: Studies show that people can tolerate elevated temperatures in the presence of appreciable air movement (e.g., from using ceiling fans). This minimises the use of air-conditioners and extends their set-point temperature (Tset), resulting in energy savings in space cooling. However, there is little empirical evidence on the energy savings from using ceiling fans with Room Air-Conditioners (RACs). To address this gap, we analysed the energy performance of RACs with both fixed-speed compressors and inverter technology at different set-point temperatures and ceiling fan speed settings in 15 residential Mixed-Mode Buildings (MMBs) in India. Thermal comfort conditions (as predicted by the Indian Model for Adaptive Comfort-Residential (IMAC-R)) with minimum energy consumption were maintained at a set-point temperature (𝑇set) of 28 and 30 C and a fan speed setting of one. Compared with a Tset of 24 °C, a 𝑇set of 28 and 30 °C resulted in energy savings of 44 and 67%, respectively. With the use of RACs, a configuration with a minimum fan speed was satisfactory for an optimal use of energy and for maintaining the conditions of thermal comfort. In addition, RACs with inverter technology used 34-68% less energy than fixed-speed compressors. With the rising use of RACs, particularly in tropical regions, the study's outcomes offer a significant potential for reducing space-cooling energy consumption and the resultant greenhouse gas (GHG) emissions.

Description: To combat climate change, it is anticipated that in the coming years countries around the world will adopt more stringent policies to reduce greenhouse gas emissions and increase the use of clean energy sources. These policies will also affect the industry sector, which means that industrial production is likely to progressively shift from CO2-emitting fossil fuel sources to renewable energy sources. As a result, a region's renewable energy resources could become an increasingly important factor in determining where energy-intensive industries locate their production. We refer to this pull factor as the "renewables pull" effect. Renewables pull could lead to the relocation of some industrial production as a consequence of regional differences in the marginal cost of renewable energy sources. In this paper, we introduce the concept of renewables pull and explain why its importance is likely to increase in the future. Using the examples of direct reduced iron (DRI) and ammonia production, we find that the future costs of climate-neutral production of certain products is likely to vary considerably between regions with different renewable energy resources. However, we also identify the fact that many other factors in addition to energy costs determine the decisions that companies make in term of location, leaving room for further research to better understand the future relevance of renewables pull.

Description: Analyzing previous international and national policy processes, the study offers recommendations for leveraging the Global Stocktake's (GST) outcomes for national climate action, especially for Nationally Determined Contributions (NDCs). It emphasizes the need for coordinated efforts to ensure the results of the GST influence national political discourse. It proposes communication strategies tailored to the different stages of the NDC policy process and diverse target audiences. The paper advocates for a nuanced and strategic approach to communication and emphasizes the importance of legitimacy and complexity in engaging stakeholders at different levels of decision-making.

Description: In recent years, the public discourse on the phase-out of carbon-intensive technologies and practices has come to a near consensus that a "just transition" is required. Yet, this term seems to have as many meanings as there are stakeholders using it. The purpose of this paper is to unpack the different meanings that regional stakeholders assign to it and the underlying dimensions of in(justice) that they invoke in their political communication. To this end, we employ a policy narrative analysis to study and compare the political discourse in four European coal and carbon-intensive mining regions: Ida-Virumaa (Estonia, oil shale), the Rhenish mining region (Germany, lignite), Upper Silesia (Poland, hard coal) and Western Macedonia (Greece, lignite). Specifically, we address the following research questions: Which narratives are characterising the political discourse around just transition? Which (in)justices are being invoked? Which patterns, similarities or differences are recognizable between regions? We found that hopeful narratives describing structural change as an opportunity to reinvent the region are prevalent in all regions. Strong narratives of resistance only prevail in Upper Silesia and Ida-Virumaa where a phase-out decision has not yet been adopted. In terms of injustices, we find surprisingly little evidence that injustices related to the immediate effects of the transformation (e.g. lay-offs and compensation for workers and companies) play an important role. Instead, the aspects related to the historical injustices produced by the legacy industrial system prevail. And perhaps most importantly, questions about access and allocation of the opportunities of the imminent transition are key and should be addressed more explicitly.

Description: The QualDeEPC project is aiming to both improve quality and cross-EU convergence of Energy Performance Certificate schemes, and the link between EPCs and deep renovation: High-quality Energy Performance Assessment and Certification in Europe Accelerating Deep Energy Renovation. The objective of the project is to improve the practical implementation of the assessment, issuance, design, and use of EPCs as well as their renovation recommendations, in the participating countries and beyond. This report serves as a compilation of the project's proposal for an enhanced and converging EPC assessment and certification scheme. It aims to provide a detailed description on the set of practical concepts, policy proposals, and tools for an enhanced EPC scheme towards deep renovation, developed by the QualDeEPC project. The project's substantial proposals both on EU and national level are presented in a comprehensive and rational way, guiding the relevant stakeholders, in particular the policy makers and competed bodies, on which steps need to be followed so as the proposals to be adapted and how the specific values can be determined in MSs. Furthermore, this report includes the project's proposal for defining "Deep Energy Renovation" based on a modified nZEB-based approach. The project's priorities A) to G) addressed are presented in the following order in this document, reflecting the importance of the enhanced EPC template form and the training of EPC assessors in such schemes: A) Improving the recommendations for renovation, which are provided on the EPCs, towards deep energy renovation; E) High user-friendliness of the EPC, by way of an enhanced EPC template form, including an introduction of the proposed "Energy Rating" indicator; D) Regular mandatory EPC assessor training or examination on assessment and renovation recommendations, required for certification/accreditation and registry; B) Online tool for comparing EPC recommendations to deep energy renovation recommendations; C) Creating Deep Renovation Network Platforms (DRNPs); F) & G) Voluntary/mandatory advertising guidelines for EPCs and Improving compliance with the mandatory use of EPCs in real estate advertisement.

Description: There is a growing body of scientific evidence supporting sufficiency as an inevitable strategy for mitigating climate change. Despite this, sufficiency plays a minor role in existing climate and energy policies. Following previous work on the National Energy and Climate Plans of EU countries, we conduct a similar content analysis of the recommendations made by citizen assemblies on climate change mitigation in ten European countries and the EU, and compare the results of these studies. Citizen assemblies are representative mini-publics and enjoy a high level of legitimacy. We identify a total of 860 mitigation policy recommendations in the citizen assemblies' documents, of which 332 (39 %) include sufficiency. Most of the sufficiency policies relate to the mobility sector, the least relate to the buildings sector. Regulatory instruments are the most often proposed means for achieving sufficiency, followed by fiscal and economic instruments. The average approval rate of sufficiency policies is high (93 %), with the highest rates for regulatory policies. Compared to National Energy and Climate Plans, the citizen assembly recommendations include a significantly higher share of sufficiency policies (factor three to six) with a stronger focus on regulatory policies. Consequently, the recommendations can be interpreted as a call for a sufficiency turn and a regulatory turn in climate mitigation politics. These results suggest that the observed lack of sufficiency in climate policy making is not due to a lack of legitimacy, but rather reflects a reluctance to implement sufficiency policies, the constitution of the policy making process and competing interests.

Description: Buildings constitute one of the main GHG emitting sectors, and energy efficiency is a key lever to reduce emissions in the sector. Global climate policy has so far mostly focused on economy-wide emissions. However, emission reduction actions are ultimately sectoral, and opportunities and barriers to achieving emission reductions vary strongly among sectors. This article therefore seeks to analyse to what extent more targeted global governance may help to leverage mitigation enablers and overcome barriers to energy efficiency in buildings. To this end, the article first synthesises existing literature on mitigation enablers and barriers as well as existing literature on how global governance may help address these barriers ("governance potential"). On this basis, the article analyses to what extent this governance potential has already been activated by existing activities of international institutions. Finally, the article discusses how identified governance gaps could be closed. The analysis finds that despite the local characteristics of the sector, global governance has a number of levers at its disposal that could be used to promote emission reductions via energy efficiency. In practice, however, lacking attention to energy efficiency in buildings at national level is mirrored at the international level. Recently, though, a number of coalitions demanding stronger action have emerged. Such frontrunners could work through like-minded coalitions and at the same time try to improve conditions for cooperation in the climate regime and other existing institutions.