Energie-, Verkehrs- und Klimapolitik
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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.
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.
Sustainable urban mobility : interventions, key measures and solutions, actors, and opportunities
(2023)
Der Gebäudebereich steht nicht nur aufgrund seiner Umweltwirkungen vor großen Herausforderungen. Bei der Einhaltung der Klima- und Nachhaltigkeitsziele spielen auch die mit langen Lebens- und Nutzungsdauern von Gebäuden einhergehenden Investitionszyklen eine entscheidende Rolle. Politische und planerische Maßnahmen werden bislang hauptsächlich im Rahmen von Effizienz- und Konsistenzstrategien entwickelt und umgesetzt, um Umweltwirkungen zu minimieren. Die Suffizienzstrategie erfährt im Vergleich dazu eine deutlich geringere Aufmerksamkeit. Ziel dieses Vorhabens ist es deshalb, Suffizienz für den Gebäudebereich zu definieren, geeignete technische und organisatorische Ansätze zu ihrer Unterstützung zu identifizieren sowie Vorschläge zu ihrer Verankerung in politischen und rechtlichen Rahmenbedingungen und Instrumenten zu erarbeiten und exemplarisch darzustellen.
Exnovation und Verkehrswende : vom Automobilitätsregime zu einer nachhaltigen urbanen Mobilität
(2023)
Der Verkehrssektor ist das Sorgenkind beim Klimaschutz. Um die Klimaschutzziele zu erreichen, sind ein rascher und tiefgreifender Wandel beim Verkehr und insgesamt weniger Autoverkehr nötig. In der Verkehrspolitik werden dazu meist innovationsorientierte Strategien verfolgt. Solange das Auto aber seinen privilegierten Status als bevorzugtes Verkehrsmittel behält, wird eine Verlagerung auf innovative und nachhaltige Alternativen verhindert.
Alina Wetzchewald untersucht hier, ob und wie "Exnovation" - also die Beendigung nichtnachhaltiger Praktiken - eine urbane Verkehrswende befördern kann, sodass sich nachhaltige Innovationen und Alternativen in der Folge besser etablieren können. Die Autorin begründet die Notwendigkeit von Exnovation, erarbeitet theoriebasiert Erklärungsansätze und untersucht Exnovation am Fall der Stadt Oslo. Im Ergebnis kann sie konkrete Empfehlungen zur aktiven Gestaltung der urbanen Verkehrswende durch Exnovation ableiten.
The EU Horizon 2020 project HiEff-BioPower (grant agreement No 727330, duration: 10/2016 - 09/2021) aimed at the development of a new, innovative, fuel flexible and highly efficient biomass CHP technology for a capacity range of 1 to 10 MW total energy output, suitable e.g. for on-site generation at larger residential apartment buildings or local heat grids. The new technology shall define a new milestone in terms of CHP efficiency and contribute to a sustainable energy supply based on renewable energies using otherwise unused residual biomass. It consists of a fuel-flexible updraft gasification technology with ultra-low particulate matter emissions, an integrated gas cleaning system and a solid oxide fuel cell (SOFC). The technology shall be applicable for a wide fuel spectrum for residual biomass (wood pellets, wood chips or selected agricultural fuels like agro-pellets) and achieve high gross electric (40%) and overall (90%) efficiencies as well as almost zero gaseous and particulate matter (PM) emissions (close or below the level of detection) as non-energy benefits. At the end of the project, final technology data has become available, as well as techno-economic analyses and market studies. Based on this data, this paper presents final results from the environmental impact assessment of the new HiEff-BioPower technology.
As the climate crisis is accelerating and the pressure to act is steadily increasing, many companies are claiming themselves or their products carbon neutral. This is usually achieved by offsetting residual emissions with carbon certificates (carbon offsetting). However, recent revelations about the inadequate quality of carbon credits and legal uncertainties surrounding the use of such offset claims are increasingly raising doubts about this approach.
This Wuppertal Report examines how the EU can promote integrity in corporate climate action. Taking into account the new framework of the Paris Agreement, the paper outlines various options for how the EU could push for more integrity and effectively combat greenwashing through the targeted use of Article 6 of the Paris Agreement.
In their recommendations, the authors advocate addressing the most serious consequences of ongoing offset practices through increased regulation of offset claims. If a ban on offset claims cannot be implemented, claims requirements and carbon offset regulations should be further specified, for example, by prohibiting any type of double counting of emissions reductions. In addition to tightening the rules for corporate offset claims within Europe, the EU could help partner countries make informed decisions when approving climate change mitigation measures and respective carbon credits. The report also emphasizes the EU's special role in international climate negotiations, where it should advocate for a strong legal framework for climate action under Article 6.
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.
Junge Menschen sehen sich durch die Klimakrise einer Einschränkung ihrer Entfaltungs- und Lebensmöglichkeiten gegenübergestellt. Diese explorative Studie verdeutlicht, wie sowohl die Wahrnehmung der Klimakrise, die Verantwortungsattribution, die wahrgenommene Handlungswirksamkeit und die einschlägigen Sozialisationserfahrungen milieuspezifisch strukturiert sind.
Informiert durch das Projekt Schools4Future wurden vier Leitfadeninterviews mit Schüler*innen zur Wahrnehmung und Deutung der Klimakrise geführt. Im dreischrittigen Kodierprozess der Grounded Theory konnten Muster der Betroffenheit, der Verantwortungsattribution und der Handlungsstrategien von vier jugendlichen Klimaaktivist*innen aus akademischen und prekären Herkunftsmilieus rekonstruiert werden. Während die sozial bevorteilten Jugendlichen sich als Betroffene und unter dem Fehlverhalten vorangehender Generationen leidende Gruppe wahrnehmen, sehen die sozial benachteiligten Jugendlichen die Klimakrise als ein systemisches Versagen neben anderen. Der medial so vertraute Aktivismus geht von dem gehobenen Milieu aus und verbindet sich mit Konsum als distinktive Praxis des klimafreundlichen Handelns. Im prekären Milieu zeigen sich andere Formen des stillen, konkreten und intrinsisch motivierten Engagements sowie das (schulische) Engagement als Investition in den individuellen, sozialen Aufstieg. Konsistenter Weise sehen sich die akademischen Jugendlichen als bevorteilt in der Bearbeitung der Klimakrise, dethematisieren aber, was die jungen Menschen aus dem sozial schwachen Milieu deutlich diagnostizieren: Der ökologische Fußabdruck ihres Konsums ist ungleich höher als der der benachteiligten Jugendlichen.
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.
Junge Menschen sehen sich durch die Klimakrise einer Einschränkung ihrer Entfaltungs- und Lebensmöglichkeiten gegenübergestellt. So überrascht es nicht, dass gerade die junge Generation sich aktiv für mehr Klimaschutz einsetzt - doch sind es wirklich alle Jugendlichen, die auf die Straße gehen? Die vorliegende explorative Studie zeigt auf, wie sowohl die Wahrnehmung der Klimakrise, die Handlungsmuster und auch die Verantwortungsattribution - individuell, innergenerational und politisch - milieuspezifisch verhandelt werden. Informiert durch das Projekt Schools4Future wurden vier Leitfadeninterviews mit Schüler*innen zur Wahrnehmung und Deutung der Klimakrise geführt. Im dreischrittigen Kodierprozess der Grounded Theory konnten Muster der Betroffenheit, der Verantwortungsattribution und der Handlungsstrategien von vier jugendlichen Klimaaktivist*innen aus akademischen und prekären Herkunftsmilieus rekonstruiert werden.
Seit Einführung der ersten Wärmeschutzverordnung in den 1970er Jahren als Antwort auf die Ölkrise sind die energetischen Anforderungen an Gebäude kontinuierlich gestiegen. Heute werden sie im
Gebäudeenergiegesetz (GEG) geregelt, das aktuell erneut novelliert wird. Trotz dieser kontinuierlichen Verschärfungen der Anforderungen ist der Endenergiebedarf von Wohngebäuden in Deutschland in den letzten Jahrzehnten kaum gesunken. Ein wesentlicher Grund hierfür ist die ebenso kontinuierlich steigende Wohnfläche pro Person.
Since the introduction of Germany's first Thermal Insulation Ordinance in the 1970s in response to the oil crisis, requirements for the energy performance of buildings have consistently increased.
Today, these are ruled by the German Building Energy Act, which is currently being amended. Despite this continuous tightening of regulations, the energy consumption in German housing has hardly decreased. The continuous increase in residential space per person is a significant reason for this.
In view of the accelerating climate crisis, the Russian invasion of Ukraine highlighted the dependency of fossil fuels on the part of Germany and the European Union (EU). With the priority aim to reduce the import dependency from the Russian Federation while providing energy security and staying on track with climate mitigation efforts, the Federal Government was presented with major challenges. Prior to the war, an approximate 34% of the mineral oil, 53.6% of the natural gas, and 50% of hard coal supplies to Germany originated from Russian sources. As of 2023, however, Germany is independent from Russian energy imports. This paper examines implications of the global energy crisis induced by the invasion on the energy sector in Germany. As a basis for achieving this analysis, a short overview of the energy situation in the country before the war and a demonstration of the provisional conditions is presented. This is followed by an analysis of the main consequences of the war and medium and long-term strategies to reach Germany's climate goals while maintaining energy security. Lastly, foreseeable consequences regarding the European and German climate goals are discussed.
Das derzeitige, auf privaten Pkw basierende Mobilitätssystem ist nicht nachhaltig: Es trägt zum Klimawandel bei, ist sozioökonomisch ungerecht, benachteiligt Frauen und Personen, die sich um den Haushalt kümmern, gefährdet die Gesundheit und verstellt den städtischen Raum. Mobilitätsdaten bieten völlig neue Möglichkeiten, um diese Probleme durch eine bessere Planung, Organisation und Umsetzung von Mobilität und Verkehr zu überwinden. Dieses Strategiepapier schlägt zwei Möglichkeiten vor, um Mobilitätsdaten für ökologische Nachhaltigkeit und gerechten Zugang zum Verkehr in Deutschland zu nutzen.
The current, private car-based mobility system is not sustainable: it contributes to climate change, it is unjust from gender- and socio-economic perspectives, endangers health and obstructs urban space. To counteract this, mobility data offers entirely new avenues for planning, organizing, and implementing mobility and transport. This strategy paper considers two possible ways to use mobility data for improving environmental sustainability and equitable access to transportation in Germany.
Das Ziel einer urbanen Verkehrswende ist klar definiert: mehr Fläche für städtisches Leben, weniger Lärm und klimaschädliche Emissionen und eine saubere Luft. Das bedeutet weniger Autoverkehr in den Städten und mehr Wege zu Fuß, mit dem Fahrrad, dem Tretroller oder mit dem öffentlichen Verkehr. Dabei reicht es nicht aus nur auf Innovationen und attraktive Alternativen zu setzen - es braucht auch Exnovation, also restriktive und reduzierende Ansätze für den Autoverkehr.
Dieser Zukunftsimpuls zeigt, wie die urbane Verkehrswende durch Exnovation beschleunigt und richtungssicher umgesetzt werden kann, welche Hemmnisse es bei bisher umgesetzten deutschen und europäischen Projekten gibt und welche Strategie- und Handlungsempfehlungen sich daraus ableiten lassen.
The objectives of the urban mobility transition have been clearly set out: gaining more space for urban living, reducing noise and emissions that have a negative impact on the climate and improving air quality. That means less traffic in cities and more trips made using environmentally-friendly modes of transport - i.e., walking, cycling or foot scooters or public transport. In transport policy, the focus is generally on innovative approaches to shaping the mobility transition.
This paper aims to explain the concept of exnovation in the context of the urban mobility transition and to underpin it using specific practical examples. In the course of this process, it is intended to identify the obstacles that stand in the way of rolling out the concept on an area-wide basis in order to deduce strategies and courses of action for expanding the concept in the future.
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.
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 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.
Analyzing previous international and national policy processes, the study offers recommendations for leveraging the Global Stocktake's (GST) outcomes for national climate action, especially for Nationally Determined Contributions (NDCs). It emphasizes the need for coordinated efforts to ensure the results of the GST influence national political discourse. It proposes communication strategies tailored to the different stages of the NDC policy process and diverse target audiences. The paper advocates for a nuanced and strategic approach to communication and emphasizes the importance of legitimacy and complexity in engaging stakeholders at different levels of decision-making.
Most air-conditioned buildings in India operate as Mixed-Mode Buildings (MMBs), either fully air-conditioned or with natural ventilation depending on the weather. Energy consumption for space cooling is a vital end-use service in buildings. Air-conditioning is expected to increase significantly due to high growth estimates in building construction, sales of Room Air-Conditioners (RACs), and real income growth. Therefore, this thesis examines the most influential design and control parameters that influence the potential of MMBs in India in relation to their thermal and energy performance. The primary features of MMBs analysed in the research project are as follows: shutting windows at night makes night ventilation redundant; natural ventilation through ceiling fans and windows is utilised to maintain optimal thermal conditions in naturally-ventilated mode and RACs are employed in air-conditioned mode. This thesis poses three research questions and aims to answer them. Firstly, what are the research gaps in assessing thermal and energy performance in mixed-mode buildings in India? Secondly, what is their potential concerning key operating conditions, and which parameters affect this potential? Lastly, how can these influential parameters be optimised? To answer these questions, three research methods were employed: 1) literature review; 2) large-scale simulation of building energy performance combined with uncertainty and sensitivity analysis; and 3) field studies of user behaviour with regards to RACs and the impact of ceiling fans and RACs on indoor conditions and energy consumption. The study identifies the cooling set point temperature as the most influential control parameter. In general, input parameters related to building design, shape and geometry were considered more important than those related to construction parameters. Furthermore, the study highlights that a set point temperature of 28 or 30°C is sufficient to maintain indoor comfort according to the Indian Model for Adaptive Comfort (IMAC) for residential buildings. If a specific airflow is required, it would use the least energy to run the ceiling fan at a low speed, usually set at 1.
Die Schaffung von bezahlbarem und sozial gerechtem Wohnraum stellt eine zentrale Herausforderung der nachhaltigen Stadtentwicklung dar. Zur Begegnung dieser Herausforderungen spielen innovative Wohnformen wie gemeinschaftliche Wohnprojekte eine bedeutende Rolle, da sie vielfältige soziale Nachhaltigkeitsaspekte aufweisen und dadurch zu einer nachhaltigen Stadtentwicklung beitragen können. In diesem Kontext bleibt die Frage offen, ob die Gemeinschaften in Wohnprojekten nach ihrer Gründung beständig bleiben. Das Ziel der Arbeit war die Beantwortung der folgenden Forschungsfrage: "Wie können gemeinschaftliche Wohnprojekte dauerhaft in Bezug auf ihre Weiterentwicklung bestehen bleiben und somit langfristig eine nachhaltige Stadtentwicklung unterstützen?"
Zur Beantwortung der Forschungsfrage wurde eine qualitative Studie in Form von narrativen Interviews mit Bewohner:innen gemeinschaftlicher Wohnprojekte durchgeführt. Die Ergebnisse aus Literatur und Praxis konnten acht besonders relevante Faktoren für die Beständigkeit von gemeinschaftlichen Wohnprojekten identifizieren: Soziale Durchmischung, Organisationsstruktur, Gemeinschaftspflege, Vertrauen, Soziales Netzwerk, Kommunikationskultur, gelebte Nachhaltigkeit, Flexibilität und Anpassungsfähigkeit. Diese Faktoren ermöglichen eine nachhaltige und anpassungsfähige Gemeinschaft, welche zu einer nachhaltigen Stadtentwicklung beitragen kann. Dafür sollten gemeinschaftliche Wohnprojekte ihre vorhandenen Potenziale weiterhin ausbauen.
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.
Im September 2023 sind zwei wenig ermutigende Untersuchungen veröffentlicht worden: Das Klimasekretariat der Vereinten Nationen macht in seinem Report zur ersten Globalen Bestandsaufnahme (Global Stocktake) deutlich, dass die bisher zugesagten nationalen Klimaschutzbeiträge bei weitem nicht genügen, um die Pariser Klimaschutzziele zu erreichen. Auch das Update zur Einhaltung der planetaren Grenzen fällt ernüchternd aus: In sechs von neun Bereichen sind die Grenzen teils weit überschritten - auch in Bezug auf den Klimawandel.
Allerdings reichen die ergriffenen Klimaschutzmaßnahmen nicht aus, um die gesteckten Ziele zu erreichen. Suffizienzstrategien und -politik können den Wandel bringen - bei Konsum, Gebäuden, Verkehr, Kreislaufwirtschaft und Energie, wie der Zukunftsimpuls zeigt.
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.
This Wuppertal Paper analyses the energy transition models of Colombia and Germany. The emphasis of the exercise is on an analysis of options for the complete decarbonization of the energy system in Colombia as a Global South country. To this end, it analyses the current situation, projections, public policy and narratives, and contrasts it with Germany as one of the countries of the Global North with which Colombia has historically maintained energy trade relations and is currently collaborating in the exploration of energy alternatives for decarbonization.
Detailed analysis of sectoral energy consumption in Colombia shows the sectors with the highest fossil energy consumption (in this order): transport (fuels), industry (gas, coal), electricity generation (gas, coal) and residential (gas). We show the projected increase in demand for fuels and electricity, and calculate the amount of electricity theoretically needed to substitute fossil sources in each sector. We estimate the total electricity required for decarbonization via sector coupling and derive a first estimation of the range of additional renewable energy capacities needed to supply this demand. We find that required capacities are expectedly large (56-110 GW), depending on decarbonization pathways, and that export capacity beyond national demand may be limited.
Our analysis of the policy and scenario arena in both countries finds that Colombia is still lacking both sector-specific decarbonization strategies and an embedding in a systemic vision of a systemic energy transition. Germany has more advanced sector strategies and (national) systemic visions, but lacks embedding assumptions on energy imports in a global-system analysis, i.e. in the analysis of an energy transition in potential exporting countries like Colombia. We formulate requirements to close these gaps in our conclusions.
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.
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.
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.
Am frühen Sonntagmorgen des 20. November 2022 ging die 27. Konferenz der Vertragsparteien des Rahmenübereinkommens der Vereinten Nationen über Klimaänderungen (27th Conference of the Parties to the United Nations Framework Convention on Climate Change (UNFCCC), COP27) im ägyptischen Scharm El Sheikh zu Ende. Geplant war die Konferenz bis Freitag. Doch es gab viel zu diskutieren. Katastrophale Extremwetterereignisse wie die Überschwemmungen in Pakistan und historische Dürren in Europa unterstrichen auch dieses Jahr wieder die Bedeutung von ambitionierten klimapolitischen Entschlüssen. Auch der neueste Bericht des Weltklimarats (Intergovernmental Panel on Climate Change, IPCC) hatte erneut hervorgehoben, dass diese Ereignisse weiter eskalieren werden, je mehr die globale Erwärmung zunimmt.
At the next United Nations (UN) climate conference in the United Arab Emirates at the end of 2023, the first Global Stocktake (GST) of the Paris Agreement is due to conclude. The main goal of this process is to feed into a new round of Nationally Determined Contributions (NDCs) by Parties to the Agreement for 2035. In addition, the GST is aimed at identifying opportunities for strengthening international cooperation to achieve the Paris goals. The GST represents the first opportunity for Parties and other stakeholders to collectively highlight opportunities for international climate cooperation. Specifically, outcomes should plant the seeds for the development of concrete sectoral decarbonization roadmaps that could guide international cooperation in years to come.
Der Wärmesektor hat einen Anteil von rund 55 Prozent am deutschen Primärenergieverbrauch, wobei der Anteil klimafreundlicher Wärmeerzeugung (erneuerbare Energien und Abwärmenutzung) bislang aber noch sehr gering ist und unter 20 Prozent liegt. Entsprechend sind die Potenziale zur Erschließung von Dekarbonisierungserfolgen im Wärmesektor besonders groß. Ein Gelingen der Wärmewende ist daher zwingende Voraussetzung dafür, dass die nationalen Klimaschutzziele erreicht werden.
Gerade Städte spielen auf Grund des hohen Energie- und Ressourcenverbrauchs, der hohen örtlichen Dichte von Infrastrukturen und durch die Vielzahl von Akteuren eine zentrale Rolle bei der Energiewende und für den Klimaschutz. So bilden beispielsweise gewachsene Strukturen im Bestand und hohe Nutzungsdichten potenzielle Restriktionen für die Integration von Technologien zur effizienten Nutzung erneuerbarer Energiequellen. Städtische Quartiere sind gleichzeitig der sinnvollste Umsetzungsmaßstab für integrierte innovative Systeme, da hier die größten Synergieeffekte zwischen Effizienzmaßnahmen und nachhaltiger Energieerzeugung erschlossen werden können.
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.
Der Anteil erneuerbarer Energien bei der Wärme- (und Kälte-)Versorgung lag 2021 in Deutschland bei 16,5 % (knapp 200 TWh/a). Davon stammten 86 % aus Biomasse und davon wiederum 47% allein aus Holzfeuerungen im häuslichen Bereich. Der Rest der erneuerbaren Wärme stammte aus oberflächennaher Geothermie und Umgebungswärme (Wärmepumpen) mit 9 % und Solarthermie mit 4,2 %. Bisher vergleichsweise kleine Beiträge stammten aus der tiefen Geothermie. Im Jahr 2021 waren bezogen auf die rund 21 Millionen im Bestand befindlichen Einzelgebäudeheizanlagen (nicht Einzelraumfeuerstätten) 1,1 Mio. Wärmepumpen und 0,9 Mio. Biomassekessel im Betrieb. Hinzu kommen zusätzliche 2,5 Mio. solarthermische Anlagen mit einer Gesamtkollektorfläche von rund 21 Mio. m2. Bei den neu installierten Wärmeerzeugern konnten Wärmepumpen und Biomassekessel auch 2021 einen deutlich steigenden Absatz verzeichnen, wobei ihr Anteil an den insgesamt rund 930.000 neu installierten Wärmerzeugern bei knapp 25% lag.
Doch 2021 nutzten immer noch rund 19 Mio. Wärmeerzeuger Gas und Öl. Darüber hinaus müssen in Wohngebäuden auch noch Etagenheizungen und veraltete Biomasseheizsysteme ausgetauscht werden. Für eine erfolgreiche Wärmewende bis 2045 im Gebäudewärmebereich müssen also weiterhin jedes Jahr rund eine Million neue komplett Erneuerbare-Heizanlagen installiert und in Betrieb genommen werden. Nach dem Anschluss an zumindest perspektivisch vollständig erneuerbar versorgte Wärmenetze sind für alle anderen Objekte Wärmepumpen, Wärmepumpen-Biomasse-Hybride und, nur wo es keine anderen Möglichkeiten gibt, reine Biomassekessel zu installieren. Alle Lösungen lassen sich zusätzlich mit Solarthermieanlagen ergänzen. Im Vergleich zu Erdgasthermen ist jedoch allein die Installation der deutlich komplexeren Systeme mit mindestens dem doppelten Zeitaufwand zu veranschlagen, während die Branche bereits heute über einen realen Fachkräftemangel klagt. Es braucht also wirksame Lösungsansätze der Forschung zur Überwindung dieser und vieler anderer Hemmnisse zur erfolgreichen Wärmewende bis 2045.