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Gaining deep leverage? : Reflecting and shaping real-world lab impacts through leverage points
(2024)
Real-world laboratories (RwLs) are gaining further traction as a means to achieve systemic impacts towards sustainability transformation. To guide the analysis of intended impacts, we introduce the concept of leverage points, discerning where, how, and to what end RwLs intervene in systems. Building on conceptual reasoning, we further develop our argument by exploring two RwL cases. Examining RwLs through the lens of the leverage points opens the way for a balanced and comprehensive approach to systemic experimentation. We invite RwL researchers and practitioners to further advance RwLs' transformative capacity by targeting the design and emerging direction of a system, contributing to a culture of sustainability.
Ways of evaluating the societal impact of real-world labs as a transdisciplinary and transformative research format are under discussion. We present an evaluation approach rooted in structuration theory, with a focus on structure-agency dynamics at the science-society interface. We applied the theory with its four modalities (interpretation schemes, norms, allocative and authoritative resources) to the case of the Mirke neighbourhood in Wuppertal, Germany. Six projects promoted the capacity for co-productive city-making. The effects of the projects were jointly analysed in a co-evaluation process. Previously proposed subcategories of the modalities as an empirical operationalisation were tested and confirmed as being applicable. Five new subcategories were generated. The use of the modalities seems appropriate for co-evaluation processes. The tool is practical, focused on real-world effects, and suitable for transdisciplinary interpretation processes. We encourage further empirical testing of the tool, as well as development of the subcategories.
This paper presents a novel governance concept for sustainable development, introducing the "Safe System Approach" as a transformative model that shifts focus from individual behavioural change to systemic transformation. This approach challenges traditional governance models that emphasize individual responsibility in achieving sustainable development and decarbonization. Instead, it advocates for creating an enabling environment that inherently guides individuals and communities towards sustainable actions. The Safe System Approach is centred on delivering low-carbon services across essential sectors, including electricity, mobility, industry, buildings, human settlements, and agriculture, thereby embedding sustainability as a default choice in societal systems. Drawing parallels with successful models in road safety, the paper explores the potential of this approach in urban development and climate action. It emphasizes the need for a broad coalition and integrated approaches in managing shared resources, highlighting the significance of systemic adjustments over individual behavioral change. By proposing a structure where sustainability is facilitated by the system's design, the paper builds on key concepts from seminal works by scholars like Garrett Hardin, Mancur Olson, Elinor Ostrom, and Ahrend Lijphart. It discusses the challenges and opportunities in creating safe operating spaces for sustainable development, emphasizing the need for multi-actor, multilevel governance systems that can manage shared resources sustainably and are resilient to political volatility. The paper aims to offer a robust, efficient, and inclusive pathway to sustainable development, contributing to the global discourse on environmental and social resilience.
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.
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.
The petrochemical industry is among the most relevant sectors from an economic, energetic and climate policy perspective. In Western Europe, production occurs in local chemical parks that form strongly connected and densely integrated regional clusters. This paper analyzes the structural characteristics of the petrochemical system in Germany and investigates three particularly distinct clusters regarding their challenges and chances for a transition towards climate-neutrality. For this, feedstock and energy supply, product portfolios and process integration as well as existing transformation activities are examined. We find that depending on their distinct network characteristics and location, unique and complex strategies are to be mastered for every cluster. Despite the many activities underway, none of them seems to have a strategic network to co-create a tailored defossilization strategy for the cluster - which is the core recommendation of this paper to develop.
Demand-side mitigation strategies have been gaining momentum in climate change mitigation research. Still, the impact of different approaches in passenger transport, one of the largest energy demand sectors, remains unclear. We couple a transport simulation model to an energy system optimisation model, both highly disintegrated in order to compare those impacts. Our scenarios are created for the case of Germany in an interdisciplinary, qualitative-quantitative research design, going beyond techno-economic assumptions, and cover Avoid, Shift, and Improve strategies, as well as their combination. The results show that sufficiency - Avoid and Shift strategies - have the same impact as the improvement of propulsion technologies (i.e. efficiency), which is reduction of generation capacities by one quarter. This lowers energy system transformation cost accordingly, but requires different kinds of investments: Sufficiency measures require public investment for high-quality public services, while efficiency measures require individuals to purchase more expensive vehicles at their own cost. These results raise socio-political questions of system design and well-being. However, all strategies are required to unleash the full potential of climate change mitigation.
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.
Reaching net-zero in the chemical industry : a study of roadmaps for industrial decarbonisation
(2024)
Striving to mitigate climate change, the European Union has adopted net-zero greenhouse gas emissions as a target for 2050. In this paper, European chemical industry roadmaps from the past six years are assessed and compared to uncover how the industry envisions its role in the transition to net-zero emissions. The roadmaps are assessed in terms of ambition level, technology and feedstock strategies, investment needs and costs, agency and dependency on other actors, as well as timeline and concretion. Although net-zero pathways are often drawn out in the roadmaps, some also choose to emphasize and argue for less ambitious pathways with emission reductions of only 40-60 %. The roadmaps vary widely in terms of the importance they assign to mechanical and chemical recycling, switching to biogenic carbon and carbon dioxide as feedstock, electrification and hydrogen, and carbon capture and storage. A commonality though, is that low-tech or near-term mitigation pathways such as demand reduction, reuse or material efficiency are seldom included. High investment needs are generally highlighted, as well as the need for policy to create enabling conditions, whereas the agency and responsibility of the chemical industry itself is downplayed. Our analysis highlights that the chemical industry does not yet have a strong and shared vision for pathways to net-zero emissions. We conclude that such a future vision would benefit from taking a whole value chain approach including demand-side options and consideration of scope 3 emissions.
Biodiversity is under threat all over the planet. Implementing sustainable out-of-home catering (OHC) is a key way to reduce the environmental impact of the agri-food sector. Thus far, there have been no studies that show the impact of food on biodiversity at the menu level in Germany. This means that neither commercial kitchens nor their patrons can record the biodiversity impact of the menus or dishes served there. This article describes the development of an assessment framework and some initial findings. The framework was developed on the basis of a systematic literature review and expert interviews. Taking this as a starting point, an indicator-based approach was developed with a focus on land use. The approach was then validated by assessing recipes used at OHC facilities. The results show that using the BiTe Biodiversity Index (BBI) that was developed, it is possible to assess the biodiversity impacts of meals and optimize them at the level of the dish. The article outlines the possible areas for improvement. Overall, it is clear that this approach can already be used in the OHC context today.
The international architecture competition Solar Decathlon Europe was held in Wuppertal in 2022 and focused on sustainable building and living in the city. The student teams participating in the competition developed buildings that would enable climate-friendly living and be tailored to the "Mirke" district in Wuppertal and the individual needs of the residents in this neighborhood. Not only the neighborhood was the focus of the competition, but also the residents of the Mirke district were involved in the project through a neighborhood panel. As part of the Mirke neighborhood panel, three survey waves were conducted between May 2021 and August 2022. The results and insights gained from the neighborhood panel were incorporated into the project and shared with the architectural teams participating in the competition. In addition, the results were shared and discussed with the urban development department of the city of Wuppertal, local initiatives, and other partners in the neighborhood.
Strengthening global climate governance and international cooperation for energy‐efficient buildings
(2023)
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.
"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".
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.
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.
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.
The 2015 Paris Agreement relies on Nationally Determined Contributions (NDCs) to outline each country's policies and plans for reducing greenhouse gas (GHG) emissions. To strengthen global climate action and achieve the Agreement's temperature goal, it is crucial to enhance the ambition level of NDCs every 5 years. While previous studies have explored the ambition of initial NDCs, limited research has delved into the factors driving the enhancement or lack thereof in NDCs' emission reduction plans. This study employs a mixed-method design to investigate the determinants of NDC enhancement. First, we analyse the updated or revised NDCs of 111 countries using quantitative methods. Second, we conduct qualitative case studies focusing on Brazil and South Africa. Our findings reveal that countries that engaged in stakeholder consultations with civil society, business, and labour groups prior to developing their updated or revised NDCs were more likely to enhance their greenhouse gas reduction targets. These results are further supported by the case studies. South Africa conducted comprehensive consultations and submitted an enhanced GHG target, while Brazil, which did not arrange open consultations, did not improve its target. This study underscores the significance of comprehensive and transparent stakeholder engagement processes, highlighting their potential to drive enhanced NDCs. By involving diverse stakeholders, including civil society, business, and labour groups, countries can foster greater ambition and effectiveness in their climate action, ultimately contributing to the global effort to combat climate change.
Better integration of climate action and sustainable development can help enhance the ambition of the next nationally determined contributions, as well as implementation of the Sustainable Development Goals. Governments should use this year as an opportunity to emphasize the links between climate and sustainable development.
Leftovers lovers vs. haters : a latent class analysis on dinner leftover management behaviours
(2023)
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.
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.
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.
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.
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.
Green hydrogen and synthetic fuels are increasingly recognized as a key strategic element for the progress of the global energy transition. The Middle East and North Africa (MENA) region, with its large wind and solar potential, is well positioned to generate renewable energy at low cost for the production of green hydrogen and synthetic fuels, and is therefore considered as a potential future producer and exporter. Yet, while solar and wind energy potentials are essential, other factors are expected to play an equally important role for the development of green hydrogen and synthetic fuels (export) sectors. This includes, in particular, adequate industrial capacities and infrastructures. These preconditions vary from country to country, and while they have been often mentioned in the discussion on green hydrogen exports, they have only been examined to a limited extent. This paper employs a case study approach to assess the existing infrastructural and industrial conditions in Jordan, Morocco, and Oman for the development of a green hydrogen and downstream synthetic fuel (export) sector.
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.
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).
Power-law city-size distributions are a statistical regularity researched in many countries and urban systems. In this history of science treatise we reconsider Felix Auerbach’s paper published in 1913. We reviewed his analysis and found (i) that a constant absolute concentration, as introduced by him, is equivalent to a power-law distribution with exponent ≈1, (ii) that Auerbach describes this equivalence, and (iii) that Auerbach also pioneered the empirical analysis of city-size distributions across countries, regions, and time periods. We further investigate his legacy as reflected in citations and find that important follow-up work, e.g. by Lotka (Elements of physical biology. Williams & Wilkins Company, Baltimore, 1925) and Zipf (Human behavior and the principle of least effort: an introduction to human ecology, Martino Publishing, Manfield Centre, CT (2012), 1949), does give proper reference to his discovery - but others do not. For example, only approximately 20% of city-related works citing Zipf (1949) also cite Auerbach (Petermanns Geogr Mitteilungen 59(74):74–76, 1913). To our best knowledge, Lotka (1925) was the first to describe the power-law rank-size rule as it is analyzed today. Saibante (Metron Rivista Internazionale di Statistica 7(2):53–99, 1928), building on Auerbach and Lotka, investigated the power-law rank-size rule across countries, regions, and time periods. Zipf's achievement was to embed these findings in his monumental 1949 book. We suggest that the use of “Auerbach–Lotka–Zipf law” (or "ALZ-law") is more appropriate than "Zipf's law for cities", which also avoids confusion with Zipf’s law for word frequency. We end the treatise with biographical notes on Auerbach.
Agriculture is a major sector responsible for greenhouse gas emissions. Local food production can contribute to reducing transport-related emissions. Since most of the worldwide population lives in cities, locally producing food implies practicing agriculture in urban and peri-urban areas. Exemplary, we analyze the potential to produce fresh vegetables within Berlin, Germany. We investigate the spatial extent of five different urban spaces for soil-based agriculture or gardening, i.e., non-built residential areas, allotment gardens, rooftops, supermarket parking lots, and cemeteries. We also quantify inputs required for such food production in terms of water, human resources, and investment. Our findings highlight that up to 82% of Berlin’s vegetable demand could be produced within the city, based on a reasonable validation of existing areas. Meeting this potential requires 42 km2 of urban spaces for cultivation, a considerable amount of irrigation water, around 17 thousand gardeners, and over 750 million EUR of initial investments. The final vegetable cost would be around 2 EUR to 10 EUR per kg without any profit margin. We conclude that it is realistic to produce a significant amount of Berlin's vegetable demand within the city, even if it comes with great challenges.
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.
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.
The twenty-seventh Conference of the Parties (COP27) to the United Nations Framework Convention on Climate Change (UNFCCC) in Sharm el-Sheikh made history by for the first time ever discussing and ultimately even agreeing to establish a fund to address loss and damage caused by climate change. However, the conference did little to limit the occurrence of loss and damage in the first place by containing the extent of climate change. This article discusses the conference's outcomes in the areas of mitigation and adaptation, loss and damage, the Global Stocktake, cooperation under Article 6 of the Paris Agreement, climate finance, and gender-responsiveness. While modest progress can be observed, it is too slow to actually achieve the objectives of the Paris Agreement. This pace is leading many, not least the most vulnerable countries, to search for parallel arenas of cooperation.
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.
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.
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.
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.
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.
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.
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.
In material development processes, the question if a new alloy is more sustainable than the existing one becomes increasingly significant. Existing studies on metals and alloys show that their composition can make a difference regarding the environmental impact. In this case study, a recently developed air hardening forging steel is used to produce a U-bolt as an example component in automotive engineering. The production process is analyzed regarding the environmental performance and compared with the standard quench and tempering steels 42CrMo4 and 33MnCrB5-2. The analysis is based on results from applying the method of Life Cycle Assessment. First, the production process and the alterations on material, product, and process level are defined. The resulting process flows were quantified and attributed with the environmental impacts covering Carbon Footprint, Cumulative Energy Demand, and Material Footprint as they represent best the resource-, energy- and thus carbon-intensive steel industry. The results show that the development of the air hardening forging steel leads to a higher environmental impact compared to the reference alloys when the material level is considered. Otherwise, the new steel allows changes in manufacturing process, which is why an additional assessment on process level was conducted. It is seen that the air hardening forging steel has environmental savings as it enables skipping a heat treatment process. Superior material characteristics enable the application of lightweight design principles, which further increases the potential environmental savings. The present work shows that the question of the environmental impact does not end with analyzing the raw material only. Rather, the entire manufacturing process of a product must be considered. The case study also shows methodological questions regarding the specification of steel for alloying elements, processes in the metalworking industry and the data availability and quality in Life Cycle Assessment.
The European Landscape Convention urges countries to involve stakeholders including citizens in the governance of ordinary (urban) landscapes. This paper studies conflicting stakeholder perspectives on urban landscape quality in the context of urban sustainability transitions in six European urban regions in the Netherlands, Italy, France, Croatia, Belarus and the Russian Federation. Repertory grid technique helped to identify the dimensions through which persons evaluate urban landscape quality. Ninety-three (93) interviewees elicited 1400 bipolar constructs, such as "Edible green - Concrete" or "Community, group - Loneliness". They then selected two constructs they consider most relevant in the context of urban sustainability transitions, and ranked all pictures on a 10-points scale. The rankings were analyzed using Multiple Correspondence Analysis. We find that, in spite of the many social and cultural differences between the regions, stakeholders largely agree on the preferred direction of urban transitions; more green and blue spots where people can meet and undertake joint (leisure) activities. The main conflict is between, on the one hand, a preference for organized development and beautification and, on the other hand, naturalness (permeability of soil) and organic development. The paper considers several challenges for transition governance.
Urban transitions and transformations research fosters a dialogue between sustainability transitions theory an inter- and transdisciplinary research on urban change. As a field, urban transitions and transformations research encompasses plural analytical and conceptual perspectives. In doing so, this field opens up sustainability transitions research to new communities of practice in urban environments, including mayors, transnational municipal networks, and international organizations.
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.
Household food waste is determined by a complex set of routinized behaviors, and disruption of these routines may allow for a decrease in this vast amount of food waste. The current study examines such a disruption of household routines: the meal box. The potential of meal boxes to diminish different types of household food waste is investigated for the first time, across different countries. After providing a framework comparing the effects of different types of meals on food waste, we subsequently examine the effects of subscription-based food supply (i.e., meal boxes) on total meal waste as well as on the different types of food waste: preparation, cooking, and plate waste. Our dataset contains 8747 meal observations from 955 households in six countries. Results from a Bayesian multilevel hurdle-lognormal model with random intercept show that, overall, meal boxes reduce total meal waste in comparison to traditionally cooked dinners (38% reduction). Meal boxes especially lower the occurrence and amount of pan-and-pot food that is wasted (i.e., cooking waste), and also lower the amount of meal preparation waste, yet lead to a higher occurrence of both preparation and plate waste compared to traditional meals. This shows how differences between meals affect household food waste, something that has received little prior research attention. Furthermore, whereas most prior research has focused on overall household food waste, our study illustrates that distinguishing between different types of household food waste can provide important new insights.
Causal strands for social bonds : a case study on the credibility of claims from impact reporting
(2022)
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.
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.
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.
This paper discusses options to increase mitigation ambition in crediting mechanisms that serve the Paris Agreement (PA), such as the Article 6.4 mechanism. Under the Clean Development Mechanism and other crediting mechanisms, baselines have been specified in the form of greenhouse gas (GHG) intensity factors and linked to business-as-usual developments. This means that with increasing production of goods and services through carbon market activities, absolute emissions may increase or fall only slowly. At a global level, such an approach widens the "emissions gap". To enable continued use of emissions intensity baselines in crediting mechanisms while being in line with the PA’s goal to pursue efforts to limit temperature rise to 1.5˚C, we propose to apply an "ambition coefficient" to emissions intensities of technologies when establishing the baseline. This coefficient would decrease to reflect increasing ambition over time, and reach zero when a country needs to reach net zero emissions. Due to the principle of common but differentiated responsibilities and respective capabilities, the coefficient would fall more quickly for developed than for developing countries. The latter would be able to generate emission reduction credits well beyond 2050, while for the former, crediting would stop around 2035 or before. An ambition coefficient approach would generate certainty for carbon market investors and preserve trust in international carbon markets that operate in line with the agreed, long-term ambition of the international climate regime.
Vernacular architecture's use of passive building techniques has been developed in response to the prevailing climatic conditions of the past. Today, buildings are designed with complete indifference to the climate and materials. Energy consumption in buildings is mainly connected to space cooling, supply of hot water, lighting, cooking and, use of appliances. Space cooling and lighting are directly influenced by the design of the building. Energy codes should be concerned with "sufficiency" as well as "efficiency". A more economic and ecological approach to building design is needed.
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.
The gap between the internationally agreed climate objectives and tangible emissions reductions looms large. We explore how the supreme decision-making body of the United Nations Framework Convention on Climate Change (UNFCCC), the Conference of the Parties (COP), could develop to promote more effective climate policy. We argue that promoting implementation of climate action could benefit from focusing more on individual sectoral systems, particularly for mitigation. We consider five key governance functions of international institutions to discuss how the COP and the sessions it convenes could advance implementation of the Paris Agreement: guidance and signal, rules and standards, transparency and accountability, means of implementation, and knowledge and learning. In addition, we consider the role of the COP and its sessions as mega-events of global climate policy. We identify opportunities for promoting sectoral climate action across all five governance functions and for both the COP as a formal body and the COP sessions as conducive events. Harnessing these opportunities would require stronger involvement of national ministries in addition to the ministries of foreign affairs and environment that traditionally run the COP process, as well as stronger involvement of non-Party stakeholders within formal COP processes.
Energy Efficiency First (EEF) is an established principle for European Union (EU) energy policy design. It highlights the exploitation of demand-side resources and prioritizes cost-effective options from the demand-side over other options from a societal cost-benefit perspective. However, the involvement of multiple decision-makers makes it difficult to implement. Therefore, we propose a flexible decision-tree framework for applying the EEF principle based on a review of relevant areas and examples. In summary, this paper contributes to applying the EEF principle by defining and distinguishing different types of cases - (1) policy-making, and (2) system planning and investment - identifying the most common elements, and proposing a decision-tree framework that can be flexibly constructed based on the elements for different cases. Finally, we exemplify the application of this framework with two example cases: (1) planning for demand-response in the power sector, and (2) planning for a district heating system.
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.
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.
In Germany, the number of renewable energy prosumers has increased rapidly since 2000. However, the development of prosumers has faced and will continue to face various economic, social, and technological challenges, which have triggered the emergence of a number of innovative business models (BM). This paper enriches the empirical basis for prosumer-oriented BMs by investigating two BM innovations in Germany (P2P electricity trading and aggregation of small-size prosumers) drawing on business model and socio-technical transition theories. A mix of qualitative data collection methods, including document analysis and semi-structured expert interviews, was applied. We found that while both BMs can potentially address the challenges associated with renewable energy prosumer development in Germany, small-scale prosumers’ participation in both BMs has been limited so far. We identified various internal and external drivers and barriers for scaling up these BMs for prosumer development in Germany. Despite these barriers, both aggregation and centralized P2P targeting prosumers may potentially be also taken up by incumbent market actors such as utilities. Decentralized P2P on the other hand still faces significant internal and external barriers for upscaling. Based on the analysis, the paper provides policy recommendations with respect to the identified drivers and barriers. From a theoretical perspective, our findings provide further evidence to challenge the dichotomous understanding of niche actors and incumbents, the latter of which are often theorized to be resistant to radical innovations.
Accelerating circular economy solutions to achieve the 2030 agenda for sustainable development goals
(2022)
Circular economy seems a vital enabler for sustainable use of natural resources which is also important for achieving the 2030 agenda for sustainable development goals. Therefore, a special session addressing issues of "sustainable solutions and remarkable practices in circular economy focusing materials downstream" was held at the 16th International Conference on Waste Management and Technology, where researchers and attendees worldwide were convened to share their experiences and visions. Presentations focusing on many key points such as new strategies, innovative technologies, management methods, and practical cases were discussed during the session. Accordingly, this article compiled all these distinctive presentations and gave insights into the pathway of circular economy towards the sustainable development goals. We summarized that the transition to circular economy can keep the value of resources and products at a high level and minimize waste production; the focus of governmental policies and plans with the involvement of public-private-partnership on 3Rs (reduce, reuse, and recycle) helps to improve the use of natural resources and take a step ahead to approach or achieve the sustainability.
Impact chains are used in many different fields of research to depict the various impacts of an activity and to visualize the system in which this activity is embedded. Research has not yet conceptualized impact chains specifically for energy sufficiency policies. We develop such a concept based on current evaluation approaches and extend these by adding qualitative elements such as success factors and barriers. Furthermore, we offer two case studies in which we test this concept with the responsible climate action managers. We also describe options for integrating these impact chains into different types of energy models, which are key tools in policy consulting.
The war in Ukraine is changing the political landscape at breakneck speed. How should politics and society react to high energy prices and a precarious dependence on fossil fuels imports? Can modern societies get by with much less energy? Energy sufficiency can play an important role in answering these questions. The contributions in this Special topic explore sufficiency as an interdisciplinary research topic for energy modeling, scenarios, and policy.
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.
This article enriches the existing literature on the importance and role of the social sciences and humanities (SSH) in renewable energy sources research by providing a novel approach to instigating the future research agenda in this field. Employing a series of in-depth interviews, deliberative focus group workshops and a systematic horizon scanning process, which utilised the expert knowledge of 85 researchers from the field with diverse disciplinary backgrounds and expertise, the paper develops a set of 100 priority questions for future research within SSH scholarship on renewable energy sources. These questions were aggregated into four main directions: (i) deep transformations and connections to the broader economic system (i.e. radical ways of (re)arranging socio-technical, political and economic relations), (ii) cultural and geographical diversity (i.e. contextual cultural, historical, political and socio-economic factors influencing citizen support for energy transitions), (iii) complexifying energy governance (i.e. understanding energy systems from a systems dynamics perspective) and (iv) shifting from instrumental acceptance to value-based objectives (i.e. public support for energy transitions as a normative notion linked to trust-building and citizen engagement). While this agenda is not intended to be—and cannot be—exhaustive or exclusive, we argue that it advances the understanding of SSH research on renewable energy sources and may have important value in the prioritisation of SSH themes needed to enrich dialogues between policymakers, funding institutions and researchers. SSH scholarship should not be treated as instrumental to other research on renewable energy but as intrinsic and of the same hierarchical importance.
Food production is responsible for approximately 17% of Germany's greenhouse gas (GHG) emissions. After retail, out-of-home catering is the second largest food sales channel in Germany. A variety of means on both the supply and demand side are necessary to stimulate, facilitate and encourage a more sustainable development and minimise GHG emissions in this sector. Nudges are one of these. This paper's focus lies on the demand side. Set in real-world laboratories, we use a standardised empirical approach to compare different nudging interventions belonging to the area of physical environment and consumers’ choice making process. We compare the effects of the same intervention across different settings and the effect of different, sequential nudging interventions in the same setting. Data was collected in eight workplace and school cafeterias in Germany over two project iterations (2016/2017; 2019/2020). A similar intervention design was applied. Comparability was assured by a harmonised menu. The first project iteration revealed that only one nudge (top menu position, +22.5%) led to significant increases in sustainable food choices, while results from the second iteration showed that all nudge interventions (best counter position, +11.6%; top menu position, +6,9%; label plus information, +15.9%) positively influenced consumer choice. Possible explanations such as the stricter compliance to the experimental design in the cafeterias but also societal developments such as the appearance of the Fridays for Future movement are discussed. As results vary between specific locations and settings, our findings suggest that nudges need to be adjusted to situational conditions for achieving highest efficacy.
The construction sector is the second largest area for the application for plastics. Due to the long life times of construction products, the implementation of the circular economy faces its own challenges. To investigate this challenge, the study covers a market study for Germany, voluntary take-back and recycling schemes of construction products, as well as the use of plastic recyclates in construction products. In addition, plastic packaging of construction products is covered. Opportunities and barriers to the use of recycled plastics in construction products are derived from the intersection of available technologies, recyclate supply, and technical requirements for construction products. The report concludes with recommendations to various stakeholders on how to promote the use of recyclates in construction products and their packaging. Important points here are the introduction of a recyclate quota for films as construction product packaging and the description of recycling possibilities and recyclate content in the technical documentation of construction products.
Dominant agricultural and food systems lead to continuous resource depletion and unacceptable environmental and social impacts. While current calls for changing agrifood systems are increasingly framed in the context of sustainability transitions, they rarely make an explicit link to transition studies to address these systemic challenges, nor do transition scholars sufficiently address agri-food systems, despite their global pertinence. From this viewpoint, we illustrate several gaps in the agri-food systems debate that sustainability transition studies could engage in. We propose four avenues for research in the next decade of transition research on agri-food systems: 1) Crossscale dynamics between coupled systems; 2) Social justice, equity and inclusion; 3) Sustainability transitions in low- and middle-income countries; 4) Cross-sectoral governance and system integration. We call for a decade of new transition research that moves beyond single-scale and sector perspectives toward more inclusive and integrated analyses of food system dynamics.
The COVID-19 pandemic has affected human mobility via lockdowns, social distancing rules, home quarantines, and the full or partial suspension of transportation. Evidence-based policy recommendations are urgently needed to ensure that transport systems have resilience to future pandemic outbreaks, particularly within Global South megacities where demand for public transport is high and reduced access can exacerbate socio-economic inequalities. This study focuses on Metro Manila - a characteristic megacity that experienced one of the most stringent lockdowns worldwide. It analyzes aggregated cell phone and GPS data from Google and Apple that provide a comprehensive representation of mobility behavior before and during the lockdown. While significant decreases are observed for all transport modes, public transport experienced the largest drop (-74.5 %, on average). The study demonstrates that: (i) those most reliant on public transport were disproportionately affected by lockdowns; (ii) public transport was unable to fulfil its role as public service; and, (iii) this drove a paradigm shift towards active mobility. Moving forwards, in the short-term policymakers must promote active mobility and prioritize public transport to reduce unequal access to transport. Longer-term, policymakers must leverage the increased active transport to encourage modal shift via infrastructure investment, and better utilize big data to support decision-making.
Technological breakthroughs and policy measures targeting energy efficiency and clean energy alone will not suffice to deliver Paris Agreement-compliant greenhouse gas emissions trajectories in the next decades. Strong cases have recently been made for acknowledging the decarbonisation potential lying in transforming linear economic models into closed-loop industrial ecosystems and in shifting lifestyle patterns towards this direction. This perspective highlights the research capacity needed to inform on the role and potential of the circular economy for climate change mitigation and to enhance the scientific capabilities to quantitatively explore their synergies and trade-offs. This begins with establishing conceptual and methodological bridges amongst the relevant and currently fragmented research communities, thereby allowing an interdisciplinary integration and assessment of circularity, decarbonisation, and sustainable development. Following similar calls for science in support of climate action, a transdisciplinary scientific agenda is needed to co-create the goals and scientific processes underpinning the transition pathways towards a circular, net-zero economy with representatives from policy, industry, and civil society. Here, it is argued that such integration of disciplines, methods, and communities can then lead to new and/or structurally enhanced quantitative systems models that better represent critical industrial value chains, consumption patterns, and mitigation technologies. This will be a crucial advancement towards assessing the material implications of, and the contribution of enhanced circularity performance to, mitigation pathways that are compatible with the temperature goals of the Paris Agreement and the transition to a circular economy.
In warm and hot climates, ceiling fans and/or air conditioners (ACs) are used to maintain thermal comfort. Ceiling fans provide air movement near the skin, which enhances the evaporation of sweat, reduces heat stress, and enhances thermal comfort. This is also called the cooling effect. However, AC usage behaviour and the effects of elevated air speed through the use of ceiling fans on indoor operative temperature during AC usage are not widely studied. This study investigated the optimum AC (cooling) set point temperature and air velocity necessary for maintaining thermal comfort while achieving energy conservation, in mixed-mode buildings in India, through field studies by using used custom-built Internet of Things (IOT) devices. In the current study, the results indicate a 79% probability that comfort conditions can be maintained by achieving a temperature drop of 3K. If this drop can be achieved, as much as possible, through passive measures, the duration of AC operation and its energy consumption are reduced, at least by 67.5 and 58.4%, respectively. During the air-conditioned period, there is a possibility that the cooing effect is reduced because of increase in operative temperature due to ceiling fan operation. Therefore, the optimum solution is to maintain the highest AC set point and minimum fan speed setting that are acceptable.
Cities around the globe are implementing innovative transport solutions as part of measures to address pertinent socio-economic and environmental challenges in urban areas and help drive the transition to low carbon development. Planning and implementing such solutions require an effective and collective approach that includes the needs and aspirations of all relevant stakeholders. In the planning and implementation of urban transport projects, capacity building components have assumed great significance but seem to be the most eluded activity for project implementers. The Living Lab concept, which allows for co-creation in innovation development, presents the opportunity to adopt innovative participatory approach in capacity building activities in transport projects; and is largely seen as a potential catalyst for rapid transformation to low carbon and sustainability transitions in cities. To this end, this paper highlights the usefulness of the Living Lab approach and provides some perspectives on how key elements of the approach are adapted in the process of assessing the capacity needs of nine (9) cities in planning and implementing e-mobility innovations. The cities are participating in an innovation research project. In the case studied, the project’s capacity needs assessment process was analyzed using an assessment framework built on four (4) key elements of the Living Lab approach, namely: extent of real-life contextualization, level of participation, diversity of stakeholders, and the time span of engagement. Insights from the assessment suggest that relevant project partners and city representatives with diverse expertise were actively involved from the onset and throughout the first 5 months of the project in defining and refining the capacity needs of partner cities based on local e-mobility conditions. This co-creative process helped determine priority areas where the need for capacity building mostly lied. Designing and operationalizing capacity building interventions tailored to the identified needs, as realized in the project, could therefore help build the necessary capacity and complement other measures aimed at developing e-mobility in the project’s partner cities.
How do recent changes in consumption in the wake of the COVID-19 pandemic affect the avoidance of packaging waste? How can an increase in packaging waste be countered and the previous trend towards unpackaged and reusable solutions be revived and promoted?
To tackle these questions, we use a systemic approach that regards packaging as a network of interrelated interests of industry (manufacturing and logistics), trade (retail and catering), consumers and the waste management sector. To analyse this network, we applied three methods. First, we analysed secondary sources such as surveys. Second, we conducted semi-structured interviews with seven actors from industry, consumer education and waste management in May and June 2020. Third, we used the questions from the interview guideline to do an online survey among representatives of the public waste management industry.
With the move to a hydrogen-based primary steel production envisioned for the near future in Europe, existing regional industrial clusters loose major assets. Such a restructuring of industries may result in a new geographical distribution of the steel industry and also to another quality of vertical integration at sites. Both implications could turn out as drivers or barriers to invest in new technologies and are thus important in respect to vertical integration of sites and to regional policy. This paper describes an approach to model production stock invest for the steel industries in North-Western Europe. Current spatial structures are reproduced with capacity, technical and energy efficiency data on the level of single facilities like blast furnaces. With the model developed both investments in specific technologies and at specific production sites can be modelled. The model is used to simulate different possible future scenarios. The case with a clear move to hydrogen-based production is compared to a reference scenario without technological shift. The scenarios show that existing trends like movement of production to the coast may be accelerated by the new technology but that sites in the hinterland can also adapt to a hydrogen economy. Possible effects of business cycles or a circular economy on regional value chains are explored with a Monte-Carlo analysis.
Model-based scenario analyses of future energy systems often come to deviating results and conclusions when different models are used. This may be caused by heterogeneous input data and by inherent differences in model formulations. The representation of technologies for the conversion, storage, use, and transport of energy is usually stylized in comprehensive system models in order to limit the size of the mathematical problem, and may substantially differ between models. This paper presents a systematic comparison of nine power sector models with sector coupling. We analyze the impact of differences in the representation of technologies, optimization approaches, and further model features on model outcomes. The comparison uses fully harmonized input data and highly simplified system configurations to isolate and quantify model-specific effects. We identify structural differences in terms of the optimization approach between the models. Furthermore, we find substantial differences in technology modeling primarily for battery electric vehicles, reservoir hydro power, power transmission, and demand response. These depend largely on the specific focus of the models. In model analyses where these technologies are a relevant factor, it is therefore important to be aware of potential effects of the chosen modeling approach. For the detailed analysis of the effect of individual differences in technology modeling and model features, the chosen approach of highly simplified test cases is suitable, as it allows to isolate the effects of model-specific differences on results. However, it strongly limits the model's degrees of freedom, which reduces its suitability for the evaluation of fundamentally different modeling approaches.
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.
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.
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.
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.
Making school-based GHG-emissions tangible by student-led carbon footprint assessment program
(2021)
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.
To address climate change, the decarbonisation of Germany's existing building stock urgently needs to be prioritised. However, the rate and depth of refurbishment has lagged behind official targets for years. This is a particular problem in the rental sector, where the costs and benefits of energy efficiency measures tend to be unevenly distributed between landlords and tenants (the so-called "landlord-tenant dilemma"). Within the context of the current policy landscape, investments in energy efficiency consequently make most sense for landlords if the upfront costs can be refinanced via increased rental income or reduced vacant periods. This paper seeks to investigate the validity of this statement at city level by using a large dataset from one of Germany’s main internet property platforms to examine how the willingness of tenants to pay for energy efficiency varies across residential locations in the city of Wuppertal.
The small-scale spatial analysis highlights the existence of a price premium for energy efficiency in the rental market for apartments; however, this premium is generally small (especially in comparison to other property enhancements, especially visible improvements) or even non-existent in some residential areas. Consequently, investing in energy efficiency is rarely an attractive option for landlords. Therefore, strong policy action, aligned with social and urban development policy objectives, is necessary to establish an effective incentive structure in the market and make investing in energy efficiency more attractive for both landlords and tenants.
The ambition to reach climate-neutral energy systems requires profound energy transitions. Various scenario studies exist which present different options to reach that goal. In this paper, key strategies for the transition to climate neutrality in Germany are identified through a meta-analysis of published studies, including scenarios which achieve at least a 95 % greenhouse gas emissions reduction by 2050 compared to 1990. It has been found that a reduction in energy demand, an expansion of domestic wind and solar energy, increased use of biomass as well as the importation of synthetic energy carriers are key strategies in the scenarios, with nuclear energy playing no role, and carbon capture and storage playing a very limited role. Demand-side solutions that reduce the energy demand have a very high potential to diminish the significant challenges of other strategies, which are all facing certain limitations regarding their sustainable potential. The level and and type of demand reductions differ significantly within the scenarios, especially regarding the options of reducing energy service demand.
The rising popularity and strong increase in the number of electric bicycles make it necessary to consider the built-in resources as well as possible treatments after the use phase. The time lag between the purchase and the occurrence of relevant defects suggests significant increases in defective components. Especially the great dynamics of the market due to regular innovations, product renewals, and the lack of spare parts availability for older models make the long-term use by customers much more difficult than for conventional bicycles. Therefore, it is necessary to analyze circular business models for the electric bicycle market. In this way, the required structures for a sustainable electric bicycle industry can be created so that valuable materials do not go into disposal but undergo a new use phase. Based on the results of "AddRE-Mo-Value Preservation Scenarios for Urban Electromobility of Persons and Loads through Additive Manufacturing and Remanufacturing," a research project funded by the German Federal Ministry of Education and Research, this paper addresses four circular business models, two sales models, and two service models. The guiding research interest of this paper is the combination of remanufacturing and additive manufacturing from a business model perspective, analyzing the extent to which additive remanufacturing can be considered a solution for electric bicycles' circularity. After describing the approach and methods used to develop these four circular business models the business models are described and analyzed using the Business Model Canvas. Based on this analysis, it is shown that the combination of remanufacturing and additive manufacturing can be applied to the electric bicycle market and be integrated into both sales and service models. The description of these business models will help managers design viable business models in the context of sustainable electric bicycles. It also shows that the individual partners within the value chain must collaborate more closely. In the electric bicycle industry, a single company will probably not be able to close the product cycle completely. Further research is needed to develop concepts of the business models and examine their practical feasibility in technical and organizational operations to achieve a circular economy.
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.
Practices and research on measuring traditionally urban sustainability abound, therefore the challenge now is related to how the urban carbon issues are included into current measuring methods, thus there is a need to develop methods for measuring urban low-carbon sustainability. In this paper, a simple method, which is based on low-carbon sustainability index, is developed. The overall urban low-carbon sustainability index is the weighted sum of 11 single indices, and each single index is defined as the indicator assessing the development level against the baseline. The baseline is often the criteria or the minimum requirement of low-carbon sustainability. Case studies in four Chinese cities have put this method into practice, and the results show that all four selected cities fail to pass the testing of sensible low-carbon sustainability rule and they are all in weakly low-carbon sustainable development. Although the four cities have made great progress in their capacity building on pollution control and their capacities on wastewater treatment, main pollutants' removal and household and hazardous wastes treatment are enough to meet the needs of local development, they are all facing the great challenges on using of sustainable energy, offsetting of CO2 emissions and adoptions of nature-based solutions. The method developed by this research is a useful tool for decision makers identifying whether the local development is not on a low-carbon sustainable path.
In Germany, the consumer sector "food" is responsible for around 15% of greenhouse gas emissions (GHG). Due to the high demand for food outside the home, changes in this area have the potential to significantly boost climate-efficient nutrition, and this includes changes in school kitchens. Currently, about 264 kg of GHG emissions per year are attributable to the food served to each school child who has school lunch year-round.
Therefore, the project "Climate and Energy Efficient Cooking in Schools" ("Klima- und Energieeffiziente Küche in Schulen” or KEEKS for short) sought to determine the status quo in the kitchens of 22 all-day schools serving a total of 5,000 lunches per day. This was done by taking energy measurements and analyzing the equipment, technology and processes used in the kitchens, and by interviewing kitchen managers using guided interviews. Greenhouse gas emissions arising from menus and kitchen processes were calculated, potential savings were identified, and recommendations for action were developed and tested. The most effective measures - the reduction and substitution of meat and meat products and the establishment of efficient waste management systems - save around 10% of a school kitchen’s greenhouse gas emissions. The recommendations that have been developed can support kitchen staff in designing a climate-friendly, child-friendly, healthy and affordable menu in the school kitchen.
Every diet has an impact on an individual's health status, the environment as well as on social aspects. In particular, ecological and social concerns are usually only vaguely assessed in the daily routines of out-of-home catering and a systematic sustainability assessment of meals is usually not carried out. Since May 2018, the menu calculator presented in this paper has been supporting stakeholders in various catering establishments with their sustainability assessment. The tool was developed within the NAHGAST project (www.nahgast.de) in cooperation with five practice partners and tested and validated by a total of 120 recipes. This article provides an overview of selected recipes' sustainability assessments (meals with fish and meat as well as vegetarian and vegan meals) and highlights the effects on the ecological, health and social dimensions.
The widely recognised Energiewende, ("energy transition") in Germany has lost its original momentum. We therefore address the question of how the transition process to a new energy system can be reignited. To do so, we developed the "5Ds approach", which lays the groundwork for a process analysis and the identification of important catalysts and barriers. Focusing on the five major fields required for the energy transition, we analyse the effects of: (1) Decarbonisation: How can efficiency and renewable energies be expanded successfully? (2) Digitalisation: Which digital solutions facilitate this conversion and would be suitable as sustainable business models? (3) Decentralisation: How can potential decentralised energy and efficiency opportunities be developed? (4) Democratisation: How can participation be strengthened in order to foster acceptance (and prevent "yellow vest" protests, etc.)? (5) Diversification of service: Which services can make significant contributions in the context of flexible power generation, demand-side management, storage and grids? Our paper comes to the conclusion that German policy efforts in the "5D" fields have been implemented very differently. Particularly with regard to democratisation, the opportunities for genuine participation among the different social actors must be further strengthened to get the Energiewende back on track. New market models are needed to meet the challenges of the energy transition and to increase the performance of "5D" through economic incentives.
2020 was meant to be the year of climate ambition. Then the COVID-19 pandemic struck, the Glasgow conference was postponed to November 2021, and climate policy generally appeared to have been put on the backburner. But towards the end of the year prospects seemed to brighten with a series of zero-emission pledges and the election of Joe Biden as US President. This article analyses what the year of the pandemic achieved in terms of combating climate change. This article first summarizes the virtual events that were organised to substitute for the physical UNFCCC conferences and what progress was or was not made on the outstanding items of the "Paris rulebook", implementation of the Gender Action Plan, and other items. Subsequently, the article surveys the status of NDC updates and to what extent recovery programmes have been used to advance climate action. Finally, the article takes a closer look at the current dynamics among non-Party actors. In summary, while formal negotiations essentially stopped in the year of the pandemic, the conservation did not. However, implementation is still lagging far behind the ambitious targets that have been set. While implementation is mostly the domain of national policy, the international process has a number of options at its disposal to foster climate action.
This paper argues that, although Japan's and Germany's energy transition paths differ in detail, a trend towards decentralisation is clearly evident in both countries. Based on comprehensive screening, own stocktaking and the results of a stakeholder dialogue, this paper highlights the motivation for different local actors to enter the energy market in both countries. Although there are challenges to success in a market dominated by large energy companies, this paper argues that the benefits to local communities outweigh the efforts. Overall, it is shown that democratisation and the decentralisation of the energy system are suitable to facilitate a successful transformation process in both countries.
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.
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.
The target of zero emissions sets a new standard for industry and industrial policy. Industrial policy in the twenty-first century must aim to achieve zero emissions in the energy and emissions intensive industries. Sectors such as steel, cement, and chemicals have so far largely been sheltered from the effects of climate policy. A major shift is needed, from contemporary industrial policy that mainly protects industry to policy strategies that transform the industry. For this purpose, we draw on a wide range of literatures including engineering, economics, policy, governance, and innovation studies to propose a comprehensive industrial policy framework. The policy framework relies on six pillars: directionality, knowledge creation and innovation, creating and reshaping markets, building capacity for governance and change, international coherence, and sensitivity to socio-economic implications of phase-outs. Complementary solutions relying on technological, organizational, and behavioural change must be pursued in parallel and throughout whole value chains. Current policy is limited to supporting mainly some options, e.g. energy efficiency and recycling, with some regions also adopting carbon pricing, although most often exempting the energy and emissions intensive industries. An extended range of options, such as demand management, materials efficiency, and electrification, must also be pursued to reach zero emissions. New policy research and evaluation approaches are needed to support and assess progress as these industries have hitherto largely been overlooked in domestic climate policy as well as international negotiations.
This paper presents an approach for assessing lifestyle carbon footprints and lifestyle change options aimed at achieving the 1.5 °C climate goal and facilitating the transition to decarbonized lifestyles through stakeholder participatory research. Using data on Finland and Japan it shows potential impacts of reducing carbon footprints through changes in lifestyles for around 30 options covering food, housing, and mobility domains, in comparison with the 2030 and 2050 per-capita targets (2.5-3.2 tCO2e by 2030; 0.7-1.4 tCO2e by 2050). It discusses research opportunities for expanding the footprint-based quantitative analysis to incorporate subnational analysis, living lab, and scenario development aiming at advancing sustainability science on the transition to decarbonized lifestyles.
Energy sufficiency is one of the three energy sustainability strategies, next to energy efficiency and renewable energies. We analyse to what extent European governments follow this strategy, by conducting a systematic document analysis of all available European National Energy and Climate Plans (NECPs) and Long-Term Strategies (LTSs). We collect and categorise a total of 230 sufficiency-related policy measures, finding large differences between countries. We find most sufficiency policies in the transport sector, when classifying also modal shift policies to change the service quality of transport as sufficiency policies. Types of sufficiency policy instruments vary considerably from sector to sector, for instance the focus on financial incentives and fiscal instruments in the mobility sector, information in the building sector, and financial incentive/tax instruments in cross-sectoral application. Regulatory instruments currently play a minor role for sufficiency policy in the national energy and climate plans of EU member states. Similar to energy efficiency in recent decades, sufficiency still largely referred to as micro-level individual behaviour change or necessary exogenous trends that will need to take place. It is not treated yet as a genuine field of policy action to provide the necessary framework for enabling societal change.
For achieving a transition towards sustainable development, central importance is attached to science and education, and especially higher education. Suitable formats are needed for empowering students to perform transformative research. On the basis of transdisciplinary and transformative real-world laboratory research and futures studies, we develop encompassing learning and teaching module: the Transformative Innovation Lab (til). The lab builds on insights into five key competencies and three types of knowledge needed for developing socially robust sustainability innovations. In this paper, the main features of this experiential and reflexive format are presented and linked to a handbook for facilitating the lab. Central learnings for implementing the format in existing study programmes from two test runs at two German universities are shared and discussed.
On the one hand, a large number of companies have committed to achieve net zero emissions and many of them foresee to offset some remaining emissions with carbon credits, suggesting a surge of future demand. Yet, the supply side of the voluntary carbon market is struggling to align its business model with the new legal architecture of the Paris Agreement. This article juxtaposes these two perspectives. It provides an overview of the plans of 482 major companies with some form of neutrality/net zero pledge and traces the struggle on the supply side of the voluntary carbon market to come up with a viable business model that ensures environmental integrity and contributes to achieving the objectives of the Paris Agreement. Our analysis finds that if carbon credits are used to offset remaining emissions against neutrality objectives, these credits need to be accounted against the host countries' Nationally Determined Contributions (NDCs) to ensure environmental integrity. Yet, operationalizing this approach is challenging and will require innovative solutions and political support.
Key policy insights:
There is a growing mismatch between the faith placed in carbon credits by private sector companies and the continued quest for a common position of the main suppliers of the voluntary carbon market.
The voluntary carbon market has not yet found a way to align itself with the new legal architecture of the Paris Agreement in a credible and legitimate way.
Public policy support at the national and international level will be needed to operationalize a robust approach for the market’s future activities.
Cross-country evidence on the adoption of energy-efficient retrofit measures (EERMs) in residential buildings is critical to supporting the development of national and pan-European policies aimed at fostering the energy performance upgrade of the building stock. In this light, the aim of this paper is to advance in the understanding of the probability of certain EERMs taking place in eight EU countries, according to a set of parameters, such as building typology, project types, and motivation behind the project. Using these parameters collected via a multi-country online survey, a set of discrete-choice (conditional logit) models are estimated on the probability of selecting a choice of any combination of 33 EERMs across the sampled countries. Results show that actions related to the building envelope are the most often-addressed across countries and single building elements or technology measures have a higher probability of being implemented. The modelling framework developed in this study contributes to the scientific community in three ways: (1) establishing an empirical relationship among EERMs and project (i.e., retrofit and deep retrofit), (2) identifying commonalities and differences across the selected countries, and (3) quantifying the probabilities and market shares of various EERMs.
The data centre industry (DCI) has grown from zero in the 1980s, to enabling 60% of the global population to be connected in 2021 via 7.2 million data centres. The DCI is based on a linear economy and there is an urgent need to transform to a Circular Economy to establish a secure supply chain and ensure an economically stable and uninterrupted service, which is particularly difficult in an industry that is comprised of ten insular subsectors. This paper describes the CEDaCI project which was established to address the challenge in this unique sector; this ground-breaking project employs a whole systems approach, Design Thinking and the Double Diamond methods, which rely on people/stakeholder engagement throughout. The paper reviews and assesses the impact of these methods and project to date, using quantitative and qualitative research, via an online sectoral survey and interviews with nine data centre and IT industry experts. The results show that the project is creating positive impact and initiating change across the sector and that the innovative output (designs, business models, and a digital tool) will ensure that sectoral transformation continues; the project methods and structure will also serve as an exemplar for other sectors.
Citizen science is a transdisciplinary approach that responds to the current science policy agenda: in terms of supporting open science, and by using a range of science communication instruments. In particular, it opens up scientific research processes by involving citizens at different phases; this also creates a range of opportunities for science communication to happen This article explores methodological and practical characteristics of citizen science as a form of science communication by examining three case studies that took different approaches to citizens' participation in science. Through these, it becomes clear that communication in citizen science is "always" science communication and an essential part of "doing science".
Cities and urban consumers play a central role in the transition to a decarbonized society. Building on existing studies that identify the significant contributions of lifestyle changes, this study proposes a practical methodology for modeling and exploring city-specific carbon footprint reduction pathways through lifestyle changes to decarbonization. It uses an input-output approach with mixed-unit consumption data and the concept of adoption rates, which is applicable to multiple cities with widely available subnational household consumption data. This paper illustrates the use of this methodology by exploring the consumption-based mitigation pathways of 52 Japanese cities with 65 lifestyle change options covering mobility, housing, food, consumer goods, and leisure domains. The results revealed that city-specific impacts of a variety of lifestyle change options can differ by as much as a factor of five among cities, even in the urban context within the same country. Due to this city-level heterogeneity, the priority options of decarbonized lifestyles, such as among shared mobility, low-carbon diets, and longevity of consumer goods, have shifted between cities. The analysis suggests that ambitious urban lifestyle changes can potentially reduce their carbon footprints to meet the 1.5 ℃ target. However, due to the overlaps of mitigation potentials between multiple lifestyle change options, the necessary levels of adoption and coverage are extensive (i.e., adoption rates of 0.6-0.9). Importantly, adopting lifestyle changes with an efficiency strategy (e.g., the introduction of end-use technologies) or sufficiency strategy (e.g., behavioral changes in consumption amounts and modes) alone is not enough; the only way to succeed is through the combination of both strategies. This paper calls for a target-based exploration and identification of city-specific priorities of lifestyle change options to facilitate consumption-oriented mitigation policies and stakeholder actions to address the climate impacts of urban consumption.
Course change: navigating urban passenger transport toward sustainability through modal shift
(2022)
Staying within the 2 °C (preferably 1.5 °C) limit requires fast and fundamental system changes, also in urban passenger transport. Shifting car traffic to environmentally friendly transport modes is one central strategy to make urban transport more sustainable and climate friendly. However, in most cities car use remains high. Therefore, this paper analyzes what course change is needed regarding direction, scale and speed of change for urban sustainability and climate protection reasons. The paper analyzes the role of modal shift as a strategy in itself and in relation to land-use (avoid) and efficiency (improve) measures. The paper draws on insights from European frontrunning cities and explorative forecasting scenarios calculated with the sophisticated integrated land-use transport model "Ruhr Region 2050". The paper suggests that a significant reduction of urban car use is needed (direction) that roughly equals a fast halving of car use (scale), which has proven feasible under the current socio-political conditions by annual reduction rates of 0.5 to 1.5 percentage points of the trip-based modal share of car use (speed). Significantly reducing car use requires comprehensive and high-intensive measures that go far beyond usual practices. Modal shift measures need to play a crucial role in integrated approaches with land-use (avoid) and efficiency (improve) measures because they have the potential to significantly reduce car use and CO2 emissions and because they can produce comparatively fast effects - which makes modal shift measures first aid approaches to achieve a fast "bending of the curve" of excessive car use and growing CO2 emissions.
The article introduces and exemplifies the approach of evidence-based narratives (EBN). The methodology is a product of co-design between policy-making and science, generating robust intelligence for evidence-based policy-making in the Directorate General for Research and Innovation of the European Commission (DG RTD) under the condition of high uncertainty and fragmented evidence. The EBN transdisciplinary approach tackles practical problems of future-oriented policy-making, in this case in the area of programming for research and innovation addressing the Grand Societal Challenge related to climate change and natural resources. Between 2013 and 2018, the EU-funded RECREATE project developed 20 EBNs in a co-development process between scientists and policy-makers. All EBNs are supported with evidence about the underlying innovation system applying the technological innovation systems (TIS) framework. Each TIS analysis features the innovation, its current state of market diffusion and a description of the innovation investment case. Indicators include potential future market sizes, effects on employment and environmental and social benefits. Based on the innovation and TIS function analyses, the EBNs offer policy recommendations. The article ends with a critical discussion of the EBN approach.
Reuse is still seen as a "niche phenomenon" and consumers seem to waste economic opportunities linked to buying and selling second-hand products. For this reason, this paper focuses on incentives and barriers to sell and buy second-hand products, as indicated in the literature, and applies a theoretical framework of transaction costs to explain the existing consumption patterns. For this paper, a representative online survey was conducted in which 1023 consumers in Germany participated, age 16 and older. The data were analyzed for statistically significant deviations between different groups of economic actors selling or buying second-hand products. Results show that valuable unused products exist in households, but barriers such as uncertainties about the reliability of the buyer or the quality of the product hinder the transition into sustainable consumption. Different forms of transaction costs are important explanatory variables to explain why consumers nevertheless predominantly buy new products, although they are aware that second-hand would save money and make an individual contribution to climate protection.