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The earth's capacity to absorb greenhouse gases is ultimately a critical limiting factor in the handling of metals. The fact that the demand for metals far exceeds their secondary production is extremely problematic at this point. Nevertheless, metals are crucial for climate protection and energy system transformation. Examples are the rare earth metal neodymium used in high-performance permanent magnets in wind turbines, the alkali metal lithium as the most important component in batteries, or the metal tellurium used in thin-film solar cells to generate solar power. It is therefore essential to promote the aspects of resource efficiency and to strengthen the critical role of metals in national and European policy programs. Next to a global solution, a European solo effort with predominantly market-based instruments and the effects of committed behaviour by civil society in the European Union (EU), show that the EU can make a considerable contribution to sustainable development on its own. Thus, a comprehensive approach is needed for sustainable metal management in the sense of a circular economy on the European level fostering sustainable production and consumption pathways. But, this need and the special role of metals are not seen in the current debate about resources in society and politics. Due to the fact that in public perception, metallic raw materials are often discussed as less urgent than energy or polymer raw materials, this article aims to highlight the critical role of metals. Further, the objective of this contribution is to show which prerequisites exist for the development and establishment of a holistic metal management and where political strategies have to start. Challenges needed to be overcome to achieve such a holistic metal strategy and management are highlighted. In particular, the role of the metal industry, circular product design and labelling and corresponding indicator systems is examined. In addition, the special role of digitalisation is being worked out. Finally, conclusions are drawn and shown which aspects have to be considered for a holistic metal strategy and management.

The transdisciplinary research mode has gained prominence in the research on and for sustainability transformations. Yet, solution-oriented research addressing complex sustainability problems has become complex itself, with new transdisciplinary research formats being developed and tested for this purpose. Application of new formats offers learning potentials from experience. To this end, we accompanied fourteen research projects conceptualized as real-world labs (RwLs) from 2015 to 2018. RwLs were part of a funding program on "Science for Sustainability" in the German federal state of Baden-Württemberg. Here, we combine conceptual and empirical work to a structured collection of experiences and provide a comprehensive account of RwLs. First, we outline characteristics of RwLs as transformation oriented, transdisciplinary research approach, using experiments, enabling learning and having a long-term orientation. Second, we outline eleven success factors and concrete design notes we gained through a survey of the 14 RwLs: (1) find the right balance between scientific and societal aims, (2) address the practitioners needs and restrictions, (3) make use of the experimentation concept, (4) actively communicate, (5) develop a "collaboration culture", (6) be attached to concrete sites, (7) create lasting impact and transferability, (8) plan for sufficient time and financial means, (9) adaptability, (10) research-based learning, and (11) recognize dependency on external actors. Characteristics and success factors are combined to illustrate practical challenges in RwLs. Third, we show which methods could be used to cope with challenges in RwLs. We conclude discussing the state of debate on RwLs and outline future avenues of research.

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.

Since the middle of the 20th century, human society experiences a "Great Acceleration" manifesting in historically remarkable growth rates that create severe sustainability problems. The globally exploding potentials of information and knowledge exchange have been and are vital drivers for this acceleration. Society has now come to the point that it requires a "Great Transformation" towards sustainability to ensure the viability of the planet for a vital society. The energy transition plays a central role for this transformation. In this context, human society has developed a comparably good understanding of the necessary infrastructural changes of this transition. For transforming the patterns of energy production and use in an energy transition as part of the "Great Transformation", this process of change now needs to strengthen its focus on information, communication, and knowledge systems. Human society needs to establish a knowledge system that has the potential to create usable knowledge for sustainability solutions. This requires organizing a communication system that is sufficiently complex, interconnected, and, at the same time, efficient for integrating reflexive, open-ended, inter- and transdisciplinary learning, evaluation, and knowledge co-production processes across multiple levels. This challenge opens a wide field of research. This cumulative dissertation contributes to research in this direction by applying a systemic sustainability perspective on the content and organization of communication in the field of research on sustainable energy and the operational level of municipal climate action as part of the energy transition. Regarding sustainability, this thesis uses strong sustainability and its principles as a frame for evaluating the content of communication. Regarding the systemic perspective, the thesis particularly relies on the following theories: (i) the human-environment system model by R. Scholz as an overarching framework regarding interactions between humans and nature, (ii) social systems theory by N. Luhmann to reflect the complexity of society, (iii) knowledge management to consider the human character of knowledge and a practice-oriented perspective, and (iv) management cybernetics, in particular, the Viable System Model by S. Beer as a framework to analyze and assess organizational structures. Furthermore, the thesis leverages the potential of text mining as a method to identify and visualize patterns in texts that reflect prevalent paradigms in communication. The thesis applies the above conceptual and methodological basis in three case studies. Case Study 1 investigates the measures proposed in 16 municipal climate action plans of regional centers in Lower Saxony, Germany. It uses a text mining approach in the form of an Summary interpretation network analysis. It analyzes how different societal subsystems are connected at the semantic level and to what extent sustainability principles can be recognized. Case Study 2 analyzes and reflects paradigms and discursive network structures in international scientific publications on sustainable energy. The study investigates 26533 abstracts published from 1990 to 2016 using a text mining approach, in particular topic modeling via latent Dirichlet allocation. Case Study 3 turns again to the cases of municipal climate action in Lower Saxony examined in Case Study 1. It examines the involvement of climate action managers of these cities in multilevel knowledge processes. Using design principles for knowledge systems, it evaluates to what extent knowledge is managed in this field across levels for supporting the energy transition and to what extent local innovation potential is leveraged or supported. The three case studies show that international research on sustainable energy and municipal climate action in Germany provide promising contributions to achieve a transformation towards sustainability but do not fully reflect the complexity of society and still support a growth paradigm, in contrast to a holistic sustainability paradigm. Further, the case studies show that research and local action are actively engaging with the diversity of energy technologies but are lagging in dealing with the socio-epistemic (communication) system, especially with regard to achieving cohesion. Using the example of German municipalities, Case Studies 1 and 3 highlight the challenges of achieving coherent local action for sustainability and bottom-up organizational learning due to incomplete or uncoordinated multilevel knowledge exchange. At the same time, the studies also point out opportunities for supporting the required coherent multilevel learning processes based on local knowledge. This can be achieved, for instance, by strengthening the coordinating role of intermediary organizational units or establishing closer interactions between the local operational units and the national level. The thesis interprets and synthesizes the results of the three case studies from its systemic sustainability perspective. On this basis, it provides several generalized recommendations that should be followed for establishing viable communication systems, especially but not exclusively in policy-making: Systemic holism: Consider matter, energy, and information flows as an integrated triplet in the context of scales, structures, and time in the various subsystems. Knowledge society: Focus on the socio-epistemic (communication) system, e.g., using the perspective of knowledge systems and associated design principles considering, for instance, working environments across horizontal and vertical levels, knowledge forms and types, and knowledge processes. Sufficiency communication: Emphasize sufficiency approaches, make it attractive, and find differentiated ways for communicating them. Multilevel cohesion and innovation: Achieve cohesion between the local and higher levels and leverage local innovations while avoiding isolated local action. Organizational interface design: Define the role of organizational units by the interactions they create at the interfaces with and between societal subsystems. Local transdisciplinarity: Support local transdisciplinary approaches integrating various subsystems, especially industry, while coordinating these approaches from a higher level for leveraging local innovation. Digital public system: Exploit existing digital technologies or infrastructures in the public system and recognize the value of data in the public sphere for achieving cohesion. Beyond the above recommendations, this thesis suggests that potential for further research lies in: Advancing nature-inspired systemic frameworks. Understanding the structure and creation of human knowledge. Developing text mining methodologies towards solution-oriented approaches.

With regard to residential energy use in the European Union (EU), most studies consider potential adopters of the technology (e.g., private owners) as being the sole decision-makers in the technology selection. However, during an integrated decision-making process (e.g., a construction project) multiple stakeholders will interact, influencing each other's judgement, thereby making it difficult to discern who is affecting the final decision, and to what extent. The goal of this study is to outline the full network of stakeholders involved in the decision-making process, along with their degree of power and interaction in the technology choice. For this purpose, empirical evidence from a multi-country survey is examined using social network analysis (SNA). The information is compared across building typologies, project types and countries (i.e., Italy, Spain, Germany, Poland, the United Kingdom, France, Belgium and the Netherlands). The results demonstrate that, in EU residential buildings, potential adopters of the technology are not the only stakeholders involved in the technology selection. They are in all instances in communication with multiple stakeholders, some of whom also hold a high level of power in the decision (i.e., key persuaders). Furthermore, their level of power and communication varies substantially across building typologies, project types and countries.