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.
Although small and medium-sized enterprises (SMEs) contribute considerably to Germany's carbon emissions, regional savings and cooperative banks - SMEs' most important financiers - hardly consider this aspect in lending to these businesses. However, given Germany's commitment to climate neutrality by 2045, suitable approaches for injecting climate finance into these SME lending processes are greatly required. Against this background, the paper at hand aims to introduce the specific case of regional banks into the debate on green finance and green banking and suggest future research in this context. In discussing the state of research on the peculiarities of regional savings and cooperative banks, we outline the resulting opportunities and limitations for climate impact assessments in SME lending. We argue that while the dual bottom-line orientation of regional banks in Germany precludes them from applying simple positive or negative screenings, their in-depth knowledge about local clients and circumstances enables them to be active and engaging partners for the green transformation of SMEs. Nonetheless, we explain why developing solutions to utilise this knowledge for climate finance by integrating climate impact assessments into routine lending processes remains a particularly challenging task.
Eine zentrale Anforderung für die zukünftige Industrieproduktion ist die Klimaneutralität. Dekarbonisierte Prozesse beruhen häufig auf der direkten oder indirekten (z.B. mittels H2) Elektrifizierung. Dabei stellen sich Fragen nach der energetischen Effizienz dieser Prozesse, nach ihren Potenzialen für einen flexiblen Betrieb sowie nach der Erfüllung kreislaufwirtschaftlicher Anforderungen wie Materialeffizienz und Schließung von Stoffkreisläufen. Der Artikel betrachtet die disruptiv dekarbonisierte Erzeugung von primärem Roheisen und bewertet drei Produktionstechniken dazu.
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.
Wo werden zukünftig grüner Wasserstoff und synthetische Kraftstoffe produziert? Zu welchen Kosten können diese erzeugt werden? Und welchen Anteil hätte eine heimische Produktion daran? Die Ergebnisse der Studie MENA-Fuels zeigen, dass im Nahen Osten und Nordafrika langfristig sehr große kostengünstige Potenziale für grünen Strom, Wasserstoff und Synfuels bestehen. Die Berücksichtigung von Investitionsrisiken hat jedoch einen signifikanten Einfluss auf deren Kosten und damit auf die Wahl der potenziellen Exportländer.
Einige Klimaneutralitätsszenarien für Deutschland nehmen an, dass zukünftig "unvermeidbares" CO2, z. B. aus der Zementproduktion, als Kohlenstoffquelle für die inländische Herstellung von Kraftstoffen oder chemischen Grundstoffen genutzt wird. In diesem Artikel wird dargelegt, warum eine solche CO2-Nutzung verglichen mit einem alternativen Pfad einer geologischen Speicherung des CO2 und einem gleichzeitigen Import "grüner" Kraft- und Grundstoffe zumindest aus energetischer Sicht nachteilig erscheint.
Ob die Rückführung von industriellen und gewerblichen Sekundärkunststoffen, das heißt von Abfällen bzw. von bereits wiederaufbereiteten Kunststoffrezyklaten, gelingen kann, ist von mehreren Faktoren wie insbesondere den spezifischen Materialeigenschaften, den Mengen, in denen sie anfallen, den aktuellen Marktpreisen (auch gegenüber Neuware) und auch der räumlichen Nähe von Sortier- bzw. Wiederaufbereitungsinfrastruktur abhängig. Trotz eigentlich guter Voraussetzungen für ein werkstoffliches Recycling, gelangen einzelne in Unternehmen anfallende Abfallchargen häufig in eine thermische Verwertung, weil sich ein Recycling wirtschaftlich nicht lohnt. Grund hierfür ist unter anderem, dass der Informationsaustausch zu den oben genannten Faktoren für Unternehmen häufig noch sehr mangelhaft ist.
Aktuell in Entwicklung befindliche digitale Plattformen und Applikationen sowie zugehörige Geschäfts- und Betreibermodelle, welche Kunststoffverarbeiter untereinander sowie Wertstofferzeuger und -verwerter vernetzen sollen, können künftig höhere Recyclingquoten ermöglichen und ökologische Einsparpotenziale heben.
Der Artikel führt Entwicklungen und Ergebnisse aktueller Forschungsprojekte zu solchen Vernetzungen zusammen, zeigt die aktuelle Situation des werkstofflichen Recyclings von industriellen und gewerblichen Kunststoffabfällen auf und beleuchtet welche Voraussetzungen für eine erfolgreiche Kreislaufführung von industriellen Kunststoffen gegeben sein müssen. Es wird insbesondere analysiert, in welcher Weise digitale Technologien und die durch sie erzielbare Informationstransparenz eine verbesserte Kreislaufwirtschaft bewirken können und in welcher Weise dies Wertschöpfungsnetzwerke räumlich beeinflussen kann.
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.
Die Bundesregierung verfolgt das ambitionierte Ziel einer Beschleunigung des Ausbaus der erneuerbaren Energien auf 80 % bis 2030 bzw. einer nahezu vollständig erneuerbaren Stromversorgung 2035. Im Zuge der avisierten Elektrifizierung anderer Sektoren wie Wärme und Mobilität im Rahmen der Sektorenkopplung nimmt die Bedeutung des Stromsektors weiter zu. Angesichts der aktuellen geopolitischen Umwälzungen und den sich abzeichnenden Knappheiten für fossiles Gas wird in einer Kurzstudie evaluiert, welchen Platz Biogas in einem langfristig zukunftsfähigen Energiesystem einnehmen kann.