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Das Passivhaus Institut hat eine große Anzahl genutzter Passivhäuser in Europa messtechnisch ausgewertet und konnte nachweisen, dass der Heizwärmebedarf neu gebauter Passivhäuser im Bereich von 15 kWh/m2a liegt, was nur 10-20% des Heizwärmebedarfs des Green Building oder anderer Energiesparstandards für Gebäude in China entspricht. Mit dem Passivhaus können den Heizwärmebedarf und die CO2-Emissionen in China erheblich gesenkt werden, was für die chinesische Regierung und Gesellschaft von großer Bedeutung ist. Folglich hat China im Zeitraum 2016-2020 mehr als 10 Millionen Quadratmeter Niedrigstenergiegebäude (Passivhäuser) gebaut und wird bis 2025 weitere 50 Millionen Quadratmeter errichten. Daher ist die Hauptmotivation dieser Arbeit, den Energieverbrauch von Passivhäusern in China zu untersuchen. Ziel ist, die Anwendbarkeit der Passivhausstandards unter Berücksichtigung der chinesischen Nutzergewohnheiten und klimatischen Besonderheiten zu validieren und ergänzende Vorschläge für die Anwendung zu unterbreiten. Für diese Arbeit wurden ein Passivhaus-Wohngebäude, ein Passivhaus-Bürogebäude und ein Green Building im Deutsch-Chinesischen Ökopark Qingdao, Nordchina, als Gegenstand der Untersuchung ausgewählt. Die angewandte Forschungsmethode gliedert sich im Wesentlichen in vier Schritte: a) Einrichtung eines Energieverbrauchsüberwachungssystems, um Energieverbrauchsdaten zu erhalten. b) Passivhaus-Planungspaket (PHPP), Therm und IBE sind Simulationswerkzeuge, die in dieser Arbeit zur Bewertung des Gebäudeenergieverbrauchs und der Wärmebrücken verwendet werden. c) Vergleich der Energieverbrauchsdaten des Passivhausgebäudes mit den simulierten oder entworfenen Energieverbrauchsdaten und schließlich d) Ermittlung der Unterschiede zwischen den beiden Datensätzen durch Analyse der Ursachen, um die Energieeffizienz des Gebäudes zu optimieren und aufzuwerten. Für die Studie wurden zunächst 3-jährige Betriebsdaten des 2016 errichteten Passivhauses-Bürogebäude ausgewertet. Das Gebäudesystem wurde gemäß den Daten des hohen Energieverbrauchs im Jahr 2017 in Betrieb genommen. Danach waren die Energieverbrauchsdaten in den folgenden zwei Jahren deutlich niedriger. Dies zeigt, wie wichtig die Inbetriebnahme der HVAC-Anlage für große öffentliche Passivhausgebäude ist. Die Analyse der Energieverbrauchsdaten und der innere Komfort-Parameter für die folgenden zwei Jahre ergab, dass der Heizwärmebedarf größer war als der simulierte Wert und der Kühlbedarf gut mit dem simulierten Wert übereinstimmte. Der innere Komfort des Gebäudes wurde das ganze Jahr über innerhalb des festgelegten Komfortbereichs gehalten. Zweitens wurde ein Passivhaus-Wohngebäude mit 36 Wohneinheiten, das im Jahr 2020 fertiggestellt wurde, messtechnisch begleitet. Erstmalig wurde ein Passivhaus-Wohngebäude in China messtechnisch ausgewertet. Während des Überwachungszeitraums ergab ein umfassender Vergleich der Entwurfs- und Konstruktionstechniken zwischen dem Passivhaus-Wohngebäude und einem benachbarten als Green Building gebauten Wohngebäude, dass im Passivhaus-Wohngebäude der Heizwärmebedarf im Vergleich zu dem Green Building Wohngebäude erheblich reduziert wurde, und es wurde vorgeschlagen, dass eine groß angelegte Förderung von Passivhäusern ein vorteilhafter Weg wäre, um Chinas Dual-Carbon-Ziele zu erreichen. Nach Abschluss der Überwachung zeigte die Analyse, dass der tatsächliche Heizwärmebedarf höher war als der vorhergesagte Wert, und dass der Primärenergieverbrauch und der innere Komfort den Passivhausstandards entsprachen. Die Gründe für den höheren Heizwärmebedarf sind 1) die Belegungsrate von nur 47% (17/36) im ersten Bezugsjahr und 2) Baufeuchte und Nutzerverhalten. Die Anwendbarkeit des Passivhausstandards in der kalten Klimazone und in der Küstenregion Nordchinas wurde an den beiden ausgewählten Passivhausgebäuden nachgewiesen. Die beobachteten Ergebnisse entsprechen im Wesentlichen den Passivhausstandards. Aufgrund des Nutzerverhaltens und der Belegungsrate entspricht ein Teil der Indikatoren nicht den Erwartungen, jedoch zeigt das Passivhausgebäude herausragende Vorteile in Bezug auf Energieeinsparung und Innenraumkomfort, verglichen mit den aktuellen Green Building oder anderen Gebäudeenergieeinsparungsstandards in China. German Passive House Institute has monitored many operating passive houses in Europe to prove that the heating demand of newly built passive houses is in the range of 15 kWh/m2a, which is only 10-20% of the heating demand of Green Building Standards or other building energy-saving standards in China. The passive house can significantly decrease heating demand and reduce CO2 emissions in China, these issues are of great concern to the Chinese government and society. Consequently, China built more than 10 million square meters of ultra-low energy buildings (passive houses) in 2016-2020 and will build another 50 million square meters by 2025. Hence, to do monitoring research on the energy consumption of passive houses in China is the main motivation of this thesis. The goal is to validate and supplement the applicability of the Passive House Standards considering the Chinese user habits and local climate characteristics. One passive house residential building, one passive house office building and one Green Building in Sino-German Ecopark Qingdao in northern China are selected for this thesis. The research method used is mainly divided into four steps: a) establishing an energy consumption monitoring system to obtain energy consumption data. b) Passive House Planning Package (PHPP), Therm, and IBE are simulation tools used in this thesis to evaluate building energy consumption and thermal bridges. c) comparing the energy consumption data of the passive house building in operation with the simulated or designed energy consumption data, and then d) finding out the differences between the two sets of data, through analyzing the reasons to achieve the purpose of improving and upgrading the energy efficiency of the building. Firstly, 3 years of operational data of the passive house public building built in 2016 were analyzed. The building system was commissioned through the data of high energy consumption in 2017. Then, the energy consumption data for the subsequent 2 years were significantly lower. It showed the importance of HVAC commissioning for large passive house public buildings. The analysis of the energy consumption data and indoor environment parameters for the subsequent 2 years revealed that the space heating demand was larger than the simulated value and the cooling demand matched the simulated value well. The building’s indoor environment was maintained within the set comfort range year-round. Secondly, a passive house residential building containing 36 apartments, which was completed in 2020, was selected for monitoring. This is the first time that a passive house residential building was monitored in China. During the monitoring period, a comprehensive comparison of the design and construction techniques between the passive house residential building and a neighbouring Green Building residential building revealed that the passive house residential building would significantly reduce space heating demand, and it was suggested that large-scale promotion of passive houses would be a beneficial way to achieve China's dual carbon goals. After the monitoring was completed, the analysis showed that the actual heating demand was higher than the predicted heating demand, and the primary energy consumption and indoor comfort met the passive house standards well. The reasons for the higher heating demand are 1) the occupancy rate of only 47% (17/36) in the first moving-in year and 2) initial wall moisture and user behavior. The applicability of Passive House standards in the cold climate zone and coastal region of northern China was proven in the selected two passive house buildings. The monitored results meet basically the passive house standards. Because of the user behavior and occupation rate, part of the indicators doesn’t meet expectations, however, the passive house building shows outstanding advantages in terms of energy-saving and indoor comfort, compared with other current Green Building Standards or other building energy-saving standards in China.

The demand for effective cooling and energy storage technologies is growing continuously. The climatic changes, miniaturization, and digitalization have redefined the technological development in the cooling and energy storage industries. The global focus is on the environmental-friendly, efficient, sustainable, and scalable cooling technologies. Owing to all these factors, green alternatives to the traditional air-conditioning and refrigeration are gaining momentum. One of such green alternatives is the electrocaloric effect (ECE). The electrocaloric effect is observed in dielectric materials as they undergo an adiabatic temperature change or an isothermal entropy change under an externally applied/removed electric field. Dielectric materials are capable to store the electrical energy as well. Therefore, they are particularly interesting for the new cooling and energy storage technologies. In this work, a ferroelectric relaxor polymer, namely, Poly(vinylidene fluoride – trifluoroethylene – chlorofluoroethylene) (P(VDF–TrFE–CFE) is investigated for the electrocaloric effect through the direct and the indirect methods. The electrical energy storage properties of different compositions of P(VDF–TrFE–CFE) and their nanocomposites with inorganic 0D nanofillers are studied. Initially, the relaxor properties in six different compositions of P(VDF–TrFE–CFE) are studied. Out of these six compositions, the three compositions, 51.3/48.7/6.2, 59.8/40.2/7.3, and 70/30/8.1, are analyzed for the first time. The field induced phase transition results in a double hysteresis loop in a few compositions. Through the direct electrocaloric measurements, it is observed that the electric field induced phase transition results in a higher electrocaloric temperature change. The indirect electrocaloric measurements are conducted with and without compensating the leakage current. It is shown that the indirect method can lead to erroneous results due to the leakage current. The results obtained through the indirect measurements conducted with the leakage current compensation are comparable to the direct measurements. The electrical energy storage properties of the neat terpolymers and their nanocomposites are compared. It is observed that the stored and discharged energy densities of the nanocomposites are superior to the neat terpolymers. Dissertation, Universität Duisburg-Essen, 2022

Conflict framing-the emphasis on clashing political positions, or the reproach of one actor to another-is central in political coverage and politics. This chapter discusses its conceptualization and the subsequent consequences for citizens' political attitudes and behavior. Previous research on conflict framing has yielded mixed results, showcasing conflicts' potential to inform and engage citizens alongside fostering cynicism and polarization. In this chapter, we argue that, to understand these divergent findings, it is necessary to distinguish between different types of conflicts. To address the fragmented literature on conflict and negativity, we propose a typology of various conflict types. This typology is exemplified through a hypothetical conflict scenario centered around climate change. We evaluate the moral, political, and epistemic implications of distinct conflict frames and propose conditions under which conflicts can positively contribute to deliberative democracy. Our typology provides a starting point for further investigations into the effects of conflict frames.

Résumé. Les observations des changements de masse des glaciers sont essentielles pour comprendre la réponse des glaciers au changement climatique et aux impacts connexes, tels que le ruissellement régional, les changements écosystémiques et l'élévation du niveau de la mer à l'échelle mondiale. Les capteurs optiques et radar spatiaux permettent de quantifier les changements d'élévation des glaciers, et donc les changements de masse pluriannuels, à l'échelle régionale et mondiale. Cependant, les estimations d'un nombre croissant d'études montrent un large éventail de résultats avec des différences souvent au-delà des limites d'incertitude. Ici, nous présentons les résultats d'une expérience intercomparaison communautaire utilisant des données d'interférométrie stéréo optique spatiale (ASTER) et radar à ouverture synthétique (TanDEM-X) pour estimer les changements d'altitude pour des glaciers définis et des périodes cibles qui posent différents défis d'évaluation. En utilisant des modèles d'élévation numériques (DEM) fournis ou autotraités pour cinq sites de test, 12 groupes de recherche ont fourni un total de 97 ensembles de données de changement d'altitude spatiaux en utilisant diverses stratégies de traitement. La validation avec des données aéroportées a montré que l'utilisation d'une estimation d'ensemble promet de réduire les erreurs aléatoires provenant de différents instruments et méthodes de traitement, mais nécessite toujours une enquête et une correction plus complètes des erreurs systématiques. Nous avons constaté que la sélection de la scène, le traitement DEM et le co-enregistrement ont le plus grand impact sur les résultats. D'autres étapes de traitement, telles que le traitement des vides de données spatiales, les différences de périodes d'enquête ou la pénétration radar, peuvent toujours être importantes pour des cas individuels. Les recherches futures devraient se concentrer sur la mise à l'essai de différentes implémentations d'étapes de traitement individuelles (par exemple, le co-enregistrement) et aborder les questions liées aux corrections temporelles, à la pénétration radar, aux changements de zone glaciaire et à la conversion de densité. Enfin, notre communauté a clairement besoin de développer les meilleures pratiques, d'utiliser des logiciels ouverts et reproductibles et d'évaluer l'incertitude globale afin d'améliorer les comparaisons et de renforcer les connaissances sur les processus physiques dans les études de changement d'altitude des glaciers. Resumen. Observar los cambios en la masa de los glaciares es clave para comprender la respuesta de los glaciares al cambio climático y los impactos relacionados, como la escorrentía regional, los cambios en los ecosistemas y el aumento global del nivel del mar. Los sensores ópticos y de radar transportados por el espacio permiten cuantificar los cambios de elevación de los glaciares y, por lo tanto, los cambios de masa plurianuales, a escala regional y global. Sin embargo, las estimaciones de un número creciente de estudios muestran una amplia gama de resultados con diferencias que a menudo van más allá de los límites de incertidumbre. Aquí, presentamos el resultado de un experimento de intercomparación basado en la comunidad que utiliza datos estéreo óptico a bordo del espacio (ASTER) e interferometría de radar de apertura sintética (TanDEM-X) para estimar los cambios de elevación para glaciares definidos y períodos objetivo que plantean diferentes desafíos de evaluación. Utilizando modelos digitales de elevación (DEM) proporcionados o autoprocesados para cinco sitios de prueba, 12 grupos de investigación proporcionaron un total de 97 conjuntos de datos de cambio de elevación a bordo del espacio utilizando varias estrategias de procesamiento. La validación con datos aéreos mostró que el uso de una estimación de conjunto es prometedor para reducir los errores aleatorios de diferentes instrumentos y métodos de procesamiento, pero aún requiere una investigación y corrección más exhaustivas de los errores sistemáticos. Descubrimos que la selección de escenas, el procesamiento de DEM y el corregistro tienen el mayor impacto en los resultados. Otros pasos de procesamiento, como el tratamiento de vacíos de datos espaciales, las diferencias en los períodos de encuesta o la penetración del radar, aún pueden ser importantes para casos individuales. La investigación futura debe centrarse en probar diferentes implementaciones de pasos de procesamiento individuales (por ejemplo, registro conjunto) y abordar cuestiones relacionadas con correcciones temporales, penetración de radar, cambios en el área de los glaciares y conversión de densidad. Finalmente, existe una clara necesidad de que nuestra comunidad desarrolle las mejores prácticas, use software abierto y reproducible y evalúe la incertidumbre general para mejorar la intercomparación y potenciar los conocimientos de los procesos físicos en los estudios de cambio de elevación de glaciares. Abstract. Observations of glacier mass changes are key to understanding the response of glaciers to climate change and related impacts, such as regional runoff, ecosystem changes, and global sea-level rise. Spaceborne optical and radar sensors make it possible to quantify glacier elevation changes, and thus multi-annual mass changes, on a regional and global scale. However, estimates from a growing number of studies show a wide range of results with differences often beyond uncertainty bounds. Here, we present the outcome of a community-based inter-comparison experiment using spaceborne optical stereo (ASTER) and synthetic aperture radar interferometry (TanDEM-X) data to estimate elevation changes for defined glaciers and target periods that pose different assessment challenges. Using provided or self-processed digital elevation models (DEMs) for five test sites, 12 research groups provided a total of 97 spaceborne elevation-change datasets using various processing strategies. Validation with airborne data showed that using an ensemble estimate is promising to reduce random errors from different instruments and processing methods, but still requires a more comprehensive investigation and correction of systematic errors. We found that scene selection, DEM processing, and co-registration have the biggest impact on the results. Other processing steps, such as treating spatial data voids, differences in survey periods, or radar penetration, can still be important for individual cases. Future research should focus on testing different implementations of individual processing steps (e.g. co-registration) and addressing issues related to temporal corrections, radar penetration, glacier area changes, and density conversion. Finally, there is a clear need for our community to develop best practices, use open, reproducible software, and assess overall uncertainty in order to enhance inter-comparison and empower physical process insights across glacier elevation-change studies. الخلاصة. تعتبر ملاحظات التغيرات في كتلة الأنهار الجليدية أساسية لفهم استجابة الأنهار الجليدية لتغير المناخ والآثار ذات الصلة، مثل الجريان السطحي الإقليمي وتغيرات النظام الإيكولوجي وارتفاع مستوى سطح البحر العالمي. تتيح أجهزة الاستشعار البصرية والرادارية المحمولة في الفضاء قياس التغيرات في ارتفاع الأنهار الجليدية، وبالتالي التغيرات الكتلية متعددة السنوات، على نطاق إقليمي وعالمي. ومع ذلك، تظهر التقديرات من عدد متزايد من الدراسات مجموعة واسعة من النتائج مع وجود اختلافات غالبًا ما تتجاوز حدود عدم اليقين. هنا، نقدم نتائج تجربة مقارنة مجتمعية باستخدام بيانات الاستريو البصري المحمول في الفضاء (ASTER) وبيانات قياس التداخل بالرادار ذي الفتحة الاصطناعية (TanDEM - X) لتقدير تغيرات الارتفاع للأنهار الجليدية المحددة والفترات المستهدفة التي تشكل تحديات تقييم مختلفة. باستخدام نماذج الارتفاع الرقمية المقدمة أو ذاتية المعالجة (DEMs) لخمسة مواقع اختبار، قدمت 12 مجموعة بحثية ما مجموعه 97 مجموعة بيانات لتغيير الارتفاع المحمول في الفضاء باستخدام استراتيجيات معالجة مختلفة. أظهر التحقق من البيانات المحمولة جواً أن استخدام تقدير المجموعة يعد بتقليل الأخطاء العشوائية من الأدوات وطرق المعالجة المختلفة، ولكنه لا يزال يتطلب تحقيقًا أكثر شمولاً وتصحيحًا للأخطاء المنهجية. وجدنا أن اختيار المشهد ومعالجة DEM والتسجيل المشترك لها أكبر تأثير على النتائج. يمكن أن تظل خطوات المعالجة الأخرى، مثل معالجة فراغات البيانات المكانية أو الاختلافات في فترات المسح أو اختراق الرادار، مهمة للحالات الفردية. يجب أن تركز الأبحاث المستقبلية على اختبار التطبيقات المختلفة لخطوات المعالجة الفردية (مثل التسجيل المشترك) ومعالجة القضايا المتعلقة بالتصحيحات الزمنية واختراق الرادار وتغيرات المنطقة الجليدية وتحويل الكثافة. أخيرًا، هناك حاجة واضحة لمجتمعنا لتطوير أفضل الممارسات، واستخدام برامج مفتوحة وقابلة للتكرار، وتقييم عدم اليقين العام من أجل تعزيز المقارنة البينية وتمكين رؤى العمليات المادية عبر دراسات تغيير ارتفاع الأنهار الجليدية.

Grid parity is considered the tipping point of economic competitiveness of PV systems. However, accurately determining when grid parity is achieved hinges on the reliability and precision of the methodologies and data employed. This paper systematically reviews existing methods for assessing PV grid parity, proposes a structured three-step framework for grid parity assessment, and identifies the potential enhancements for more accurate evaluation outcomes. The framework begins with the calculation of PV costs using the Levelized Cost of Electricity (LCOE) method, continues with predicting PV cost trends through learning curves, and is completed by benchmarking PV costs against electricity prices. Our findings reveal that most current PV cost calculations for grid parity primarily rely on the LCOE method, which can be enhanced by incorporating modifications for integration costs, revenues, PV performance metrics, regional-specific characteristics, and uncertainties. Moreover, learning curve models used to predict PV cost trends can be refined by tailoring learning rates and model formulations to reflect specific stages of technological development and regional differences. Additionally, the results suggest that electricity prices used in grid parity assessment can be adjusted to reflect the impact of policies and market dynamics. This comprehensive review provides a robust framework for assessing grid parity and serves as an essential reference for conducting more precise techno-economic feasibility assessment of PV systems.

This thesis explores the impacts of the dominant business model in the fashion industry, characterized by a trend of overproduction and overconsumption, and its negative effects on the environment and on society. A comprehensive literature review aims to assess the unsustainable practices of the fashion industry, the emerging role of the slow fashion movement, and the barriers individuals face in the transition to a more sustainable consumption. The thesis analyzes consumer purchase behavior and their interest in sustainability, focusing on behavioral economics and behavioral interventions designed to increase sustainable behavior and sustainable fashion consumption, specifically the deceptive practice of greenwashing and its influence on consumers’ choices is thoroughly examined. An online experiment is conducted to test participants’ responses to four different purchase scenarios, including the disclosure of information typically hidden by brands, greenwashed claims, real sustainable claims, and an intervention involving information provision, aimed to inform respondents about the existence of the greenwashing practices. Results highlight a significant impact of authentic sustainable claims on respondents’ decisions, guiding them towards sustainable choices. Directional results also suggest the effectiveness of greenwashed claims in influencing people decision-making, attracting them towards the “fake green” and affordable fast fashion garments. Additionally, directional results indicate that disclosing information about the existence of greenwashing increases individuals’ consideration and likelihood to choose the sustainable option, the same mechanism applies when disclosing the truth about the negative impacts of producing cheap fast fashion clothes. This study contributes valuable insight to the understanding of consumer behavior in the fashion sector, examining the impact of information disclosure, greenwashing, and interventions on customer decision-making. It introduces new implications and practical in-sights, addressing the complexities of the current shift towards a sustainable fashion consumption.

Tipping points are an emerging concept in climate change research and communication. However, previous research has strongly focussed on tipping points in biophysical systems, which left the potential for climate change induced socio-economic tipping points (SETPs) mostly unexplored. The objective of this thesis is to identify and assesses SETPs in order to support decision making on climate policy. A SETP is defined as “a climate change induced, abrupt change of a socio-economic system, into a new, fundamentally different state”. SETPs are characterised by: (1) stable states at two sides of a threshold; (2) a non-linear change mechanism, and (3) rapid change while passing the threshold. Examples are: the collapse of winter sports tourism, farmland abandonment, and sea-level rise-induced migration. The clearest examples of SETPs are likely to be found on small scale homogeneous systems, that can exhibit a system-wide uniform response to a climate driver. When modelling SETPs, there is an extra layer of complexity compared to biophysical tipping points, because of the complex dynamic character of the socio-economic system and the fact that humans proactively and autonomously alter the system to anticipate biophysical change. This thesis presents a stepwise approach for identification and assessment of SETPs, which in seven steps guides the researcher through key study design choices. The first application is urban water security. The essence of urban water security lies in an adequate response to partly inevitable system pressures, with well-functioning infrastructure that prevents adverse impacts such as flood damage. At the same time, in cities under pressure, like Amsterdam and Rotterdam, flood pressures may always propagate along the cause-effect chain via an unexpected mechanism. For example, a flood or near-miss experience could lead to the SETP of an abrupt house price collapse. Stepwise SETP-assessment shows that house price collapses could happen under conditions of high-end sea level rise, reactive flood risk management, and slow measure implementation. A new policy insight is that this SETP may be avoided by managing risk perceptions; when all buyers and sellers on the housing market are aware of gradual changes in flood risk, large fluctuations in risk perceptions and related house price booms and busts may be prevented. The second application field is the road transport infrastructure of thirty European countries. The SETP investigated is an abrupt large-scale malfunctioning of the road network from a river flood event. National-scale SETPs are most likely in small mountainous countries like Slovenia, Macedonia and Albania, where the 5% least favourable small-scale flood events may already disrupt some 30-40% of the preferred routes between major economic regions. Targeted flood proofing of a few critical weak spots by road operators could be a relatively easy, yet very effective, way to enhance the network robustness. Many countries have certain regions that could abruptly become poorly accessible during river floods. Such regional-scale tipping points seem to be much more likely and policy relevant than large national-scale disruptions. The third application is winter sports tourism. For six ski resorts in the Swiss Alps, the SETP of an abrupt bankruptcy is investigated. Bankruptcy might follow when in consecutive years, the number of days with good snow conditions falls below a critical threshold. The effectiveness of incremental and more transformative adaptation, resp. artificial snowmaking and year-round business model diversification, is explicitly modelled. The resulting policy insight is that beyond 2050, low-altitude resorts cannot avoid SETPs with artificial snow making alone, and can only survive with economic diversification towards year-round, less snow-dependent activities. Higher-altitude resorts must be aware that ski lift and real estate investments come with a long-term commitment to artificial snow making to avoid SETPs.

This paper is a teaching case study written for educational purposes. The case brings forward a real-life situation of an organization that is engaged in the exciting but also risky journey of implementing a green innovation at a large scale. The case is written in a way that allows students to reflect and think about the organizational and leadership challenges and opportunities involved. The teacher can activate these reflections in the context of various possible theoreyical and analytical frameworks, in a number of possible different courses. The case is about Exergi, the main utility company producing district heating in Stockholm. After successfully transitioning from coal to bio-energy sources, since 2020 Exergi has embarked on a new and far more ambitious venture: Bioenergy Carbon Capture and Storage (BECCS). This technology captures CO2 emissions from biomass combustion and stores them, potentially resulting in negative emissions. BECCS plays a central role in IPCC mitigation pathways and Exergi has recognized an opportunity, but venturing into this uncharted territory presents numerous challenges. BECCS is a new and untested technology at an industrial scale, requiring substantial investments, and a market for selling carbon removal certificates (CRC) that does not exist yet. Though promising for reaching net zero targets in time, the viability of BECCS for Exergi depends on a supportive regulatory framework, cross-border cooperation, and the creation of a CRC market. To navigate these challenges, Exergi relies on creating an innovative organizational culture as well as mobilizing external stakeholders. Hence, CEO Anders Egelrudhas hired individuals with entrepreneurial mindsets, and sought external expertise as well as creating strong networks and communication approach. Yet, some internal tensions have also come to the fore, due to the rapid internal dynamics. Overall, Exergi's transition from coal to BECCS reflects the commitment to sustainable practices by an incumbent, and its willingnessto size new opportunities. The company's success driving this transformation forward hinges on many events coming together, both external and internal to the firm.

Reducing ecological impact is a major challenge for today’s industry, particularly the rail industry, which is one of the most energy-intensive industries. Indeed, this industry faces two paradoxical needs: on the first hand, it must decrease its energy consumption, meeting both an environmental goal and a financial objective, and on the other hand, it must not only maintain but increase the circulation of train, thus allowing a larger part of the population to use the most ecological means of land transport. Reducing consumption requires a prediction model. The formalization of this model is complex, particularly when driver control is taken into account. The complexity of the model must be chosen carefully. The SNCF has a very sophisticated model with a large number of parameters that need to be evaluated. In this work, we consider a train dynamics model simplified to a non-linear differential longitudinal dynamics equation coupled to a power balance [1]. In this model it is possible to distinguish two types of inputs:the model parameters which will be calibrated and the environment variables (wind, driver’s control, etc.) which will change from one journey to another. In order to calibrate the model, we rely on a priori knowledge from SNCF experts who provide information on the values of the model parameters. We also have a set of measurements (time, speed, power consumption, control) taken on the same train, for different journeys on different tracks. The used methodology is Bayesian calibration [2], which makes it possible to use the two types of information available to us while injecting model errors to take account of our imperfect knowledge of the system. These errors are parameterized by hyper-parameters that should also be calibrated. It is then necessary to formalize the experts’ knowledge mathematically in order to create our prior distributions, and then to write a likelihood function that will allow us to take into account both the measurements and the model errors. Another difficulty is the lack of knowledge about driver control as the control isn’t measured. The control linked to each measurement must be determined and appears in our problem asfunctional hyper-parameters.REFERENCES:[1] Julien Nespoulous, Christian Soize, Christine Funfschilling, and Guillaume Perrin. Optimisation of train speed to limit energy consumption. Vehicle System Dynamics, 60(10):3540–3557, October 2022.[2] Christian Soize. Uncertainty quantification: An accelerated course with advanced applications in computational engineering. Springer International Publishing, Cham, Switzerland, 2018.

La place centrale des savoirs dans les choix d’action publique est remise en cause par la « mise en risque » de phénomènes climatiques et hydrologiques qui s’avèrent imprévisibles et irréversibles. C’est le cas du recul du trait de côte des falaises en Picardie. Longtemps basé sur une approche scientifique et technique dite de « recul moyen », l’État doit recomposer ses moyens d’action face à l’occurrence de risques extrêmes et brusques. Or, il ne s’agit pas seulement de changer de modalités dans l’approche technique, ni de promouvoir de nouveaux outils de prévention pour construire des stratégies de recomposition territoriale des littoraux. Le cas de l’effondrement de la falaise d’Ault illustre le besoin urgent d’intégrer dans l’action publique une pluralité de connaissances des effets du changement climatique, tant en termes de savoirs qui peuvent être alternatifs et scientifiques que de connaissances tirées de l’expérience sensible, personnelle ou esthétique. The central place of knowledge in public policy choices is being challenged by climate and hydrological phenomena that turn out to be unpredictable and irreversible. This is the case with the retreat of the coastline of the cliffs in Picardy. For a long time based on a scientific and technical approach known as “average retreat”, the national government now has to reconstitute its methods of action in the face of extreme and sudden risks. But it’s not just a question of changing the technical approach, or promoting new prevention tools to build strategies for reorganising coastal areas. The case of the collapse of the cliffs at Ault illustrates the urgent need to integrate multiple forms of knowledge about the effects of climate change into public action, both in terms of alternative and scientific knowledge and in terms of knowledge rooted in sensitive, personal, or aesthetic experience. International audience